Experiment (from Lat. "Trial, experience") - the leading method of scientific knowledge, including psychological research. Aimed at identifying causal relationships. It is characterized by the creation of optimal conditions for the study of certain phenomena, as well as the purposeful and controlled change of these conditions.

Unlike observation, an experiment is an active way of knowing reality; it presupposes a scientist's planned intervention in the situation under study, and its control. If passive observation allows us to answer the questions “How? How does something happen? ", Then the experiment makes it possible to find an answer to a question of a different kind -" Why is this happening? "

One of the basic concepts when describing an experiment is a variable. This is the name of any real condition of the situation that can be changed. The experimenter manipulates variables, while the observer waits for that change to occur, which the experimenter makes at his own discretion.

Variable types:

Independent is the one that the experimenter changes.

Dependent is a factor that changes in response to the input of the independent variable.

Intermediate variables are not amenable to strict control, but certainly taken into account factors, in practice located between the independent and dependent variables, mediating their influence on each other. For example: the physiological or psychological state of the subjects (stress, fatigue, interest in work, indifference, etc.). The logic of the experiment requires that such characteristics should not be overlooked, since they can significantly change the behavior of the subjects, thereby affecting the quality of the results obtained.

Controlled variables are conditions that should not change during the experiment. Otherwise, the validity of the empirical proof will be violated: the dynamics of the dependent variable can be explained not by the influence of the independent variable, but by other, unplanned and unnoticed by the experimenter himself.

Thus, experimenting means studying the influence of independent variables on the dependent ones with constant characteristics of the controlled variables and the intermediate ones taken into account.

In science, there are two plans for conducting experiments:

Traditional, where only one independent variable changes;

Factorial, where several independent variables change simultaneously.

44. P.K. Anokhin's theory, functional system Is a dynamic set of various organs and systems of the body, which is formed to achieve a useful (adaptive) result. The theory of functional systems is a model that describes the structure of behavior; created by P.K. Anokhin. "The principle of a functional system" - the unification of private mechanisms of the body into an integral system of an adaptive behavioral act, the creation of an "integrative unit". Two types of functional systems are distinguished: Systems of the first type provide homeostasis due to the internal (already available) resources of the body, without going beyond its limits (for example, blood pressure). Systems of the second type maintain homeostasis due to changes in behavior, interaction with the outside world, and lie in the basis of various types of behavior. Stages of a behavioral act: Afferent synthesis Any excitation in the central nervous system exists in interaction with other excitations: the brain analyzes these excitations. Synthesis determines the following factors: Motivation Trigger afferentation (excitations caused by conditioned and unconditioned stimuli) Ambient afferentation (excitement from the familiarity of the environment causing the reflex and dynamic stereotypes) Memory (species and individual) Decision making Formation of an acceptor of the result of an action (creating an ideal image of a target and its retention; presumably, at the physiological level, it is an excitation circulating in the ring of interneurons) Efferent synthesis (or a stage of the action program; integration of somatic and autonomic stimuli into a single behavioral act. The action is formed, but does not manifest itself externally) Action (implementation of the behavior program) Evaluation the result of the action At this stage, the actual performed action is compared with the ideal image created at the stage of the formation of the acceptor of the result of the action (reverse afferentation occurs); based on the comparison results, the action is either corrected or terminated. Meeting the need (authorizing the cessation of activity) The choice of goals and how to achieve them are key factors governing behavior. According to Anokhin, in the structure of a behavioral act, a comparison of reverse afferentation with an acceptor of the result of an action gives positive or negative situational emotions that affect the correction or termination of actions (another type of emotion, leading emotions, is associated with the satisfaction or dissatisfaction of a need in general, that is, with the formation of a goal) ... In addition, memories of positive and negative emotions affect behavior. In general, the behavioral act is characterized by the purposefulness and active role of the subject. In psychology, the principle of developmental heterochrony is widely known. It means that different brain structures and mental functions mature at different rates and reach full maturity at different stages of development. Heterochrony of development is one of the regularities of normal ontogenesis, due to which each new stage is the result of complex interfunctional rearrangements. On this general "skeleton" of development, individual variations are superimposed, manifested in the uneven maturation of functions in a given individual: some of them are better developed in a child than on average among peers, while others are worse. Uneven development of higher mental functions (HMF) is a normal phenomenon that has an adaptive meaning - after all, it is beneficial for the population as a whole that different people have different abilities. Along with the biological factors of brain maturation, social factors play a significant role in the emergence of unevenness, including living conditions, intrafamily relationships, parental attention to certain aspects of the child's mental development.

MENTAL REALITY

(Psychic reality; Psychische Wirklichkeit) - one of the key concepts in analytical psychology; viewed as experience, as an image and as the very nature and function of the mental.

As an experience or experience, psychic reality includes everything that appears to be real to a person or contains the power of reality. According to Jung, a person experiences life and life events primarily in the categories of the truth of a subjective narrative, and not historical truth (the so-called personal myth). Experienced as a psychic reality can also be a form of self-expression. Its illustration is, among other things, the tendency of the unconscious to personify its contents. Personification for Jung was an empirical demonstration of psychic reality. The existence of opinions, beliefs, ideas and fantasies does not mean that what they relate to is exactly what they can claim to be. The psychic reality of two people, for example, will differ markedly. And an illusory system, psychologically real, will not have an objective status. The relationship of psychic reality to hypothetical, external or objective reality is important primarily from a clinical point of view. In Jung's views on psychic reality as an image, one can find their well-known opposition to the position of Freud, "whose idea of" psychic reality "never weakened his faith in an objective reality that can be discovered and then measured by scientific methods." According to Jung, consciousness has an indirect reflected nature, mediated by the nervous system and other psychosensory processes, including psycholinguistic ones. Experiences, say, excitement or pain, reach us in a secondary form. Immediate construction of images takes place, and both the outer and inner worlds are experienced with the help of the figurative system. The concepts of the inner and outer worlds themselves are also metaphorical images. The image itself is that which directly presents itself to consciousness. We become aware of our experience by colliding with its image. Jung came to the conclusion that, due to its figurative composition, psychic reality is the only reality that we can experience directly.In the aspect of psychic reality, as a designation of the nature and function of the psychic, the latter, according to Jung, acts as an intermediate world between the physical and spiritual spheres. capable of touching and mixing. Physical should be understood as both organic and inorganic aspects of the material world. The psychic arises to take a middle position between such phenomena as sensory impressions and plant or mineral life, on the one hand, and on the other, the intellectual and spiritual ability to form and perceive ideas.

V.V. Nikandrov points out that the achievement of the main goal of the experiment - the maximum possible unambiguity in understanding the connections between the phenomena of inner mental life and their external manifestations - is achieved due to the following main characteristics of the experiment:

1) the initiative of the experimenter in the manifestation of psychological facts of interest to him;

2) the possibility of varying the conditions for the emergence and development of mental phenomena;

3) strict control and fixation of conditions and the process of their occurrence;

4) the isolation of some and the accentuation of other factors that determine the studied phenomena, which makes it possible to identify the patterns of their existence;

5) the possibility of repeating the conditions of the experiment for multiple verification of the received scientific data and their accumulation;

6) varying the conditions for quantitative assessments of the revealed patterns.

Thus, a psychological experiment can be defined as a method in which the researcher himself causes the phenomena of interest to him and changes the conditions of their course in order to establish the causes of these phenomena and the patterns of their development. In addition, the scientific facts obtained can be repeatedly reproduced due to the controllability and strict control of conditions, which makes it possible to verify them, as well as the accumulation of quantitative data, on the basis of which one can judge the typicality or randomness of the phenomena under study.

4.2. Types of psychological experiment

Experiments are of several kinds. Depending on the way of organizing distinguish laboratory, natural and field experiments. Laboratory the experiment is carried out under special conditions. The researcher has a planned and purposeful effect on the object of study in order to change its state. The advantage of a laboratory experiment can be considered a strict control over all conditions, as well as the use of special equipment for measurement. The disadvantage of a laboratory experiment is the difficulty of transferring the obtained data to real conditions. The subject in a laboratory experiment is always aware of his participation in it, which can cause motivational distortions.

Natural the experiment is carried out in real conditions. Its advantage lies in the fact that the study of the object is carried out in the context of everyday life, so the obtained data can be easily transferred into reality. The subjects are not always informed about their participation in the experiment, therefore they do not give motivational distortions. Disadvantages - inability to control all conditions, unforeseen interference and distortion.

Field the experiment is carried out according to the natural scheme. In this case, it is possible to use portable equipment, which makes it possible to more accurately record the received data. The subjects are informed about the participation in the experiment, but the familiar environment reduces the level of motivational distortions.

Depending on the research objectives distinguish between exploratory, pilotage and confirmatory experiments. Search the experiment is aimed at finding a causal relationship between phenomena. It is carried out at the initial stage of the study, allows you to formulate a hypothesis, isolate the independent, dependent and side variables (see 4.4) and determine how to control them.

Aerobatic an experiment is a trial experiment, the first in a series. It is carried out on a small sample, without strict control of variables. A pilot experiment allows you to eliminate gross errors in the formulation of a hypothesis, to specify the goal, to clarify the methodology for conducting an experiment.

Confirming the experiment is aimed at establishing the type of functional relationship and clarifying the quantitative relationships between variables. It is carried out at the final stage of the study.

Depending on the nature of influence the subject is allocated ascertaining, forming and control experiments. Ascertaining an experiment includes measuring the state of an object (subject or a group of subjects) before actively influencing it, diagnosing the initial state, establishing cause-and-effect relationships between phenomena. The purpose formative experiment is the use of methods of active development or the formation of any properties in subjects. Control an experiment is a repeated measurement of the state of an object (a subject or a group of subjects) and comparison with the state before the start of the formative experiment, as well as with the state in which the control group is, which did not receive experimental influence.

By possibilities of influence the experimenter, the independent variable is distinguished between the provoked experiment and the experiment to which it is referred. Provoked an experiment is an experiment in which the experimenter himself changes the independent variable, while the results observed by the experimenter (types of reactions of the subject) are considered provoked. P. Fress calls this type of experiment "classic". Experiment, referred to, Is an experiment in which changes in the independent variable are made without the intervention of the experimenter. This type of psychological experiment is resorted to when the independent variables have an impact on the subject that is significantly extended in time (for example, the educational system, etc.). If the impact on the subject can cause a serious negative physiological or psychological disturbance, then such an experiment should not be carried out. However, there are times when a negative impact (for example, a brain injury) occurs in reality. Subsequently, such cases can be generalized and studied.

4.3. The structure of a psychological experiment

The main components of any experiment are:

1) subject (test subject or group);

2) experimenter (researcher);

3) stimulation (the method of influencing the subject chosen by the experimenter);

4) the subject's response to stimulation (his mental response);

5) the conditions of the experiment (additional to stimulation of the impact, which can affect the reactions of the subject).

The subject's response is an external reaction, by which one can judge the processes taking place in his internal, subjective space. These processes themselves are the result of the impact on him of stimulation and conditions of experience.

If the answer (reaction) of the subject is denoted by the symbol R, and the effects on him of the experimental situation (as a combination of the effects of stimulation and the conditions of the experiment) - by the symbol S, then their ratio can be expressed by the formula R = = f (S). That is, the reaction is a function of the situation. But this formula does not take into account the active role of the psyche, human personality (P). In reality, a person's reaction to a situation is always mediated by the psyche, personality. Thus, the relationship between the main elements of the experiment can be fixed by the following formula: R = f(R, S).

P. Fress and J. Piaget, depending on the objectives of the study, distinguish three classical types of relations between these three components of the experiment: 1) functional relations; 2) structural relationships; 3) differential relations.

Functional relationship characterized by the variability of the responses (R) of the subject (P) with systematic qualitative or quantitative changes in the situation (S). Graphically, these relations can be represented by the following diagram (Fig. 2).

Examples of functional relationships found in experiments: change in sensations (R) depending on the intensity of exposure to the sensory organs (S); memorization volume (R) from the number of repetitions (S); intensity of emotional response (R) on the action of various emotiogenic factors (S); development of adaptation processes (R) in time (S) etc.

Structural relationships are revealed through the system of responses (R1, R2, Rn) to various situations (Sv S2, Sn). The relationship between individual responses is structured into a system that reflects the structure of the personality (P). Schematically, it looks like this (Fig. 3).

Examples of structural relationships: the system of emotional responses (Rp R2, Rn) to stressors (Sv S2, Sn); solution efficiency (R1, R2, Rn) of various intellectual tasks (S1, S2, Sn) etc.

Differential relationships are identified through the analysis of reactions (R1, R2, Rn) of different subjects (P1, P2, Pn) for the same situation (S). The diagram of these relations is as follows (Fig. 4).

Examples of differential relationships: the difference in the reaction rate of different people, national differences in the expressive expression of emotions, etc.

4.4. Experimental Variables and Methods for Controlling Them

To clarify the ratio of all factors included in the experiment, the concept of "variable" was introduced. There are three types of variables: independent, dependent and additional.

Independent variables. The factor changed by the experimenter himself is called independent variable(NP).

The conditions in which the subject's activity is carried out, the characteristics of the tasks that are required of the subject, the characteristics of the subject himself (age, sex, other differences of the subjects, emotional states and other properties of the subject or people interacting with him) can act as NP in the experiment. Therefore, it is customary to single out the following types NP: situational, instructive and personal.

Situational NP most often are not included in the structure of the experimental task performed by the subject. Nevertheless, they have a direct impact on his activity and can be varied by the experimenter. Situational NP include various physical parameters, for example, illumination, temperature, noise level, as well as the size of the room, setting, placement of equipment, etc. an outside observer or a group of people. V.N. Druzhinin points to the peculiarities of communication and interaction between the subject and the experimenter as a special kind of situational NP. Much attention is paid to this aspect. In experimental psychology, there is a separate direction, which is called "psychology of psychological experiment."

Instructional NP are directly related to the experimental task, its qualitative and quantitative characteristics, as well as the methods of its implementation. The experimenter can manipulate the instructive NP more or less freely. He can vary the material of the task (for example, numerical, verbal or figurative), the type of response of the subject (for example, verbal or non-verbal), the assessment scale, etc. Great opportunities lie in the way of instructing the subjects, informing them about the purpose of the experimental task. The experimenter can change the means that are offered to the subject for completing the task, put obstacles in front of him, use the system of rewards and punishments in the course of the task, etc.

Personal NP are controllable features of the subject. Typically, such features are the states of the participant in the experiment, which the researcher can change, for example, various emotional states or states of working capacity-fatigue.

Each subject participating in the experiment has many unique physical, biological, psychological, socio-psychological and social characteristics that the experimenter cannot control. In some cases, you should consider these unmanaged features as additional variables and apply control methods to them, which will be discussed below. However, in differential psychological studies, when using factorial designs, uncontrolled personal variables can act as one of the independent variables (for details on factorial designs, see 4.7).

Researchers also distinguish between different kinds independent variables. Depending on the presentation scales it is possible to distinguish qualitative and quantitative NP. High-quality NP correspond to different gradations of the scales of names. For example, the emotional states of the subject can be represented by the states of joy, anger, fear, surprise, etc. Methods for completing tasks may include the presence or absence of prompts for the subject. Quantitative NP correspond to rank, proportional or interval scales. For example, the time allotted for the task, the number of tasks, the amount of remuneration based on the results of solving the tasks can be used as quantitative NP.

Depending on the the number of levels of manifestation independent variables distinguish between two-level and multi-level NP. Two-tier NP have two levels of manifestation, multilevel- three or more levels. Experimental plans of different complexity are constructed depending on the number of levels of NP manifestation.

Dependent variables. A factor whose change is a consequence of a change in the independent variable is called dependent variable(RFP). The dependent variable is the component of the subject's response that is of direct interest to the researcher. Physiological, emotional, behavioral reactions and other psychological characteristics, which can be registered in the course of psychological experiments, can be used as RFPs.

Depending on the the way in which you can check in the changes, allocate salary:

S directly observed;

S requiring physical instrumentation for measurement;

S requiring psychological measurement.

To the RFP, directly observable, include verbal and non-verbal behavioral manifestations that can clearly and unequivocally be assessed by an external observer, for example, refusal of activity, crying, a certain statement of the subject, etc. physical equipment for registration, include physiological (pulse, blood pressure, etc.) and psychophysiological reactions (reaction time, latent time, duration, speed of action, etc.). To salaries requiring psychological measurement, include such characteristics as the level of aspirations, the level of development or formation of certain qualities, forms of behavior, etc. For the psychological measurement of indicators, standardized procedures can be used - tests, questionnaires, etc. Some behavioral parameters can be measured, i.e. that is, are uniquely recognized and interpreted only by specially trained observers or experts.

Depending on the number of parameters, included in the dependent variable, distinguish between one-dimensional, multidimensional and fundamental RFP. One-dimensional ZP is represented by the only parameter, the changes of which are studied in the experiment. An example of a one-dimensional ZP is the rate of sensorimotor reaction. Multidimensional ZP is represented by a set of parameters. For example, attentiveness can be assessed by the amount of viewed material, the number of distractions, the number of correct and incorrect answers, etc. Each parameter can be recorded independently. Fundamental ZP is a variable of a complex nature, the parameters of which have some well-known relationships with each other. In this case, some parameters act as arguments, and the dependent variable itself acts as a function. For example, the fundamental measurement of the level of aggression can be viewed as a function of its individual manifestations (mimic, verbal, physical, etc.).

The dependent variable must have such a basic characteristic as sensitivity. Sensitivity ZP is its sensitivity to changes in the level of the independent variable. If, when the independent variable changes, the dependent variable does not change, then the latter is non-sensitive and it makes no sense to conduct an experiment in this case. There are two known options for the manifestation of the non-sensitivity of the RF: "ceiling effect" and "floor effect". The "ceiling effect" is observed, for example, in the case when the presented task is so simple that it is performed by all subjects, regardless of age. The “gender effect”, on the other hand, occurs when a task is so difficult that none of the subjects can cope with it.

There are two main ways of fixing changes in ZP in a psychological experiment: direct and delayed. Direct the method is used, for example, in experiments on short-term memorization. The experimenter immediately after repeating a number of stimuli fixes their number reproduced by the subject. The delayed method is used when between impact and the effect passes a certain period of time (for example, when determining the influence of the number of memorized foreign words on the success of the text translation).

Additional variables(DP) is a concomitant stimulation of the subject that influences his response. The set of DP consists, as a rule, of two groups: external conditions of experience and internal factors. Accordingly, they are usually called external and internal DPs. TO external DP includes the physical environment of the experiment (illumination, temperature, sound background, spatial characteristics of the room), parameters of the apparatus and equipment (design of measuring instruments, operating noise, etc.), time parameters of the experiment (start time, duration, etc.), the personality of the experimenter. TO internal DP include the mood and motivation of the subjects, their attitude to the experimenter and the experiments, their psychological attitudes, inclinations, knowledge, abilities, skills and experience in this type of activity, the level of fatigue, well-being, etc.

Ideally, the researcher seeks to reduce all additional variables to nothing or at least to a minimum in order to isolate "in its pure form" the relationship between the independent and dependent variables. There are several main ways to control the influence of external DPs: 1) elimination of external influences; 2) constancy of conditions; 3) balancing; 4) counterbalancing.

Elimination of external influences represents the most radical control method. It consists in the complete exclusion of any external DP from the external environment. In the laboratory, conditions are created that isolate the subject from sounds, light, vibrational influences, etc. The most striking example is the experiment on sensory deprivation, conducted on volunteers in a special chamber, completely excluding the intake of any stimuli from the external environment. It should be noted that it is practically impossible to eliminate the effects of DP, and it is not always necessary, since the results obtained in the conditions of the elimination of external influences can hardly be transferred into reality.

The next way to control is to create constant conditions. The essence of this method is to make the effects of DP constant and the same for all subjects throughout the entire experiment. In particular, the researcher seeks to make constant the space-time conditions of the experiment, the technique of its conduct, equipment, presentation of instructions, etc. With careful application of this method of control, large errors can be avoided, however, the problem of transferring the results of the experiment to conditions that are very different from the experimental ones, remains problematic.

In cases where it is not possible to create and maintain constant conditions throughout the experiment, resort to the method balancing. This method is used, for example, in a situation where the external DP is not identifiable. In this case, balancing would be to use a control group. The study of the control and experimental groups is carried out under the same conditions with the only difference that the control group does not have the effect of the independent variable. Thus, the change in the dependent variable in the control group is due only to external DP, and in the experimental one - by the joint action of external additional and independent variable.

If the external DP is known, then balancing consists in the effect of each of its values ​​in combination with each level of the independent variable. In particular, such an external DP as the sex of the experimenter, in combination with the independent variable (the sex of the subject), will lead to the creation of four experimental series:

1) male experimenter - male subjects;

2) male experimenter - female subjects;

3) female experimenter - male test subjects;

4) female experimenter - female test subjects.

In more complex experiments, balancing of several variables can be applied at the same time.

Counterbalancing as a way to control external DP is practiced most often when the experiment includes several series. The subject finds himself in different conditions sequentially, but the previous conditions can change the effect of exposure to subsequent ones. To eliminate the "sequence effect" that arises in this case, the experimental conditions are presented to different groups of subjects in a different order. For example, in the first series of the experiment, the first group is presented with the solution of intellectual problems from simpler to more complex, and the second - from more complex to simpler. In the second series, on the contrary, the first group is presented with the solution of intellectual problems from more complex to simpler, and the second - from simpler to more complex. Counterbalancing is used in cases where it is possible to conduct several series of experiments, but it should be borne in mind that a large number of attempts causes fatigue of the subjects.

Internal DP, as mentioned above, are factors that are hidden in the personality of the subject. They have a very significant effect on the results of the experiment; their effect is rather difficult to control and take into account. Among the internal DPs, one can distinguish permanent and fickle. Permanent internal DPs do not change significantly during the experiment. If the experiment is carried out with one subject, then the permanent internal DP will be his gender, age, nationality. This group of factors also includes the temperament, character, abilities, inclinations of the subject, his interests, views, beliefs and other components of the general orientation of the personality. In the case of an experiment with a group of subjects, these factors acquire the character of unstable internal LF, and then, to level their influence, they resort to special methods of forming experimental groups (see 4.6).

TO fickle internal DP refers to the psychological and physiological characteristics of the subject, which can either change significantly during the experiment, or become actualized (or disappear) depending on the goals, objectives, type, form of organization of the experiment. The first group of such factors is made up of physiological and mental states, fatigue, addiction, and the acquisition of experience and skills in the process of performing an experimental task. Another group includes the attitude towards a given experience and a given research, the level of motivation for a given experimental activity, the subject's attitude to the experimenter and his role as a subject, etc.

To equalize the effect of these variables on responses in different samples, there are a number of methods that have been successfully used in experimental practice.

To eliminate the so-called serial effect, which is based on addiction, a special order of presentation of stimuli is used. This procedure is called "balanced turn order", when stimuli of different categories are presented symmetrically relative to the center of the stimulus series. The scheme of such a procedure looks like this: A B B A, where A and V- incentives of different categories.

To prevent influence on the subject's response anxiety or inexperience introductory or preliminary experiments are being carried out. Their totals are not taken into account when processing the data.

To prevent variability in responses due to accumulation of experience and skills during the experiment, the subject is offered the so-called "exhaustive practice". As a result of this practice, the subject develops stable skills before the start of the experiment itself, and in further experiments the subject's indicators do not directly depend on the factor of accumulating experience and skills.

In cases where it is necessary to minimize the influence on the subject's response fatigue resort to the "method of rotation". Its essence lies in the fact that each subgroup of the subjects is presented with a certain combination of stimuli. The totality of such combinations completely exhausts the entire set of possible options. For example, with three types of stimuli (A, B, C), each of them is presented with the first, second and third place in presentation to the subjects. Thus, stimuli are presented to the first subgroup in the order of ABC, the second - ABB, the third - BAV, the fourth - BVA, the fifth - VAB, the sixth - SMA.

The above methods of procedural equalization of internal non-constant DPs are applicable for both individual and group experiments.

The attitude and motivation of the subjects as internal non-permanent DPs should be maintained at the same level throughout the experiment. Installation how the readiness to perceive the stimulus and respond to it in a certain way is created through the instruction given by the experimenter to the subject. In order for the setting to be exactly what is required for the research task, the instruction must be available to the subjects and adequate to the tasks of the experiment. The unambiguousness and ease of understanding of the instructions are achieved by its clarity and simplicity. In order to avoid variability in the presentation, it is recommended to read the instruction verbatim or give it in writing. Maintaining the initial setting is controlled by the experimenter through constant observation of the subject and is corrected by reminding, if necessary, of the corresponding instructions.

Motivation the subject is viewed mainly as an interest in the experiment. If there is no interest or is weak, then it is difficult to count on the completeness of the fulfillment of the tasks provided for in the experiment by the subject and on the reliability of his answers. Too high interest, "rewinding", is also fraught with inadequacy of the subject's answers. Therefore, in order to obtain an initially acceptable level of motivation, the experimenter must take the most serious approach to the formation of a contingent of subjects and the selection of factors stimulating their motivation. Competitiveness, various types of remuneration, interest in one's performance, professional interest, etc. can act as such factors.

Psychophysiological conditions the subjects are recommended not only to maintain at the same level, but also to optimize this level, that is, the subjects should be in a "normal" state. You should make sure that before the experiment, the subject did not have super-significant experiences for him, he has enough time to participate in the experiment, he is not hungry, etc. During the experiment, the subject should not be overly excited or suppressed. If these conditions cannot be met, then it is better to postpone the experiment.

From the considered characteristics of the variables and the methods of their control, it becomes clear the need for careful preparation of the experiment when planning it. In real experimental conditions, it is impossible to achieve 100% control of all variables, however, various psychological experiments differ significantly from each other in the degree of control of the variables. The next section is devoted to the question of evaluating the quality of an experiment.

4.5. Validity and reliability of the experiment

Experimental procedures are designed and evaluated using the concepts of ideal experiment, fit experiment, and endless experiment.

Perfect experiment Is an experiment organized in such a way that the experimenter changes only the independent variable, the dependent variable is controlled, and all other experimental conditions remain unchanged. An ideal experiment assumes the equivalence of all subjects, the invariability of their characteristics in time, the absence of time itself. It can never be realized in reality, since not only the parameters of interest to the researcher change in life, but also a number of other conditions.

The correspondence of a real experiment to the ideal is expressed in such a characteristic as internal validity. Internal validity indicates the reliability of the results that a real experiment provides compared to an ideal one. The more the conditions uncontrolled by the researcher influence the change in the dependent variables, the lower the internal validity of the experiment, therefore, the greater the likelihood that the facts found in the experiment are artifacts. High internal validity is the main hallmark of a well-run experiment.

D. Campbell identifies the following factors that threaten the internal validity of an experiment: background factor, natural development factor, testing factor, measurement error, statistical regression, non-random selection, screening. If they are not controlled, then they lead to the appearance of the corresponding effects.

Factor background(histories) includes events that occur between pre and final measurements that can cause changes in the dependent variable along with the influence of the independent variable. Factor natural development due to the fact that changes in the level of the dependent variable may arise in connection with the natural development of the participants in the experiment (growing up, increasing fatigue, etc.). Factor testing consists in the influence of preliminary measurements on the results of subsequent ones. Factor measurement errors associated with inaccuracy or changes in the procedure or method for measuring the experimental effect. Factor statistical regression manifests itself in the event that subjects with extreme indicators of any estimates were selected to participate in the experiment. Factor non-random selection accordingly, it occurs in cases when, when forming the sample, the selection of participants was carried out in a non-random manner. Factor screenings manifests itself in the event that the subjects drop out unevenly from the control and experimental groups.

The experimenter should consider and, where possible, limit the influence of factors that threaten the internal validity of the experiment.

Full fit experiment Is an experimental study in which all conditions and their changes correspond to reality. The approximation of a real experiment to an experiment of complete correspondence is expressed in external validity. The degree of portability of the experimental results to reality depends on the level of external validity. External validity, as defined by R. Gottsdanker, affects the reliability of conclusions, which is given by the results of a real experiment in comparison with the experiment of full compliance. To achieve high external validity, it is necessary that the levels of additional variables in the experiment correspond to their levels in reality. An experiment that has no external validity is considered invalid.

Factors that threaten external validity include the following:

Reactive effect (consists in a decrease or increase in the susceptibility of subjects to experimental influences due to previous measurements);

The effect of interaction between selection and influence (consists in the fact that the experimental influence will be significant only for the participants in this experiment);

The factor of the experimental conditions (can lead to the fact that the experimental effect can be observed only in these specially organized conditions);

The factor of interference of influences (manifests itself when one group of subjects is presented with a sequence of mutually exclusive influences).

Researchers working in the applied fields of psychology - clinical, pedagogical, organizational, are especially concerned about the external validity of experiments, since in the case of an invalid study, its results will not give anything when transferred to real conditions.

Endless experiment involves an unlimited number of experiments, samples to obtain more and more accurate results. An increase in the number of samples in an experiment with one subject leads to an increase in reliability the results of the experiment. In experiments with a group of subjects, an increase in reliability occurs with an increase in the number of subjects. However, the essence of the experiment lies precisely in the fact that, on the basis of a limited number of samples or with the help of a limited group of subjects, to identify cause-and-effect relationships between phenomena. Therefore, an endless experiment is not only impossible, but also meaningless. To achieve high reliability of the experiment, the number of samples or the number of subjects must correspond to the variability of the phenomenon under study.

It should be noted that with an increase in the number of subjects, the external validity of the experiment also increases, since its results can be transferred to a wider population. To conduct experiments with a group of subjects, it is necessary to consider the issue of experimental samples.

4.6. Experimental samples

As indicated above, the experiment can be carried out either with one subject or with a group of subjects. An experiment with one subject is carried out only in some specific situations. First, these are situations when the individual differences of the subjects can be neglected, that is, any person can be the subject (if his characteristics are studied in the experiment, as opposed to, for example, an animal). In other situations, on the contrary, the subject is a unique object (a brilliant chess player, musician, artist, etc.). Situations are also possible when the subject is required to have special competence as a result of training or extraordinary life experience (the only survivor of a plane crash, etc.). One subject is also limited in those cases when the repetition of this experiment with the participation of other subjects is impossible. For experiments with one subject, special experimental designs have been developed (for details, see 4.7).

More often, experiments are carried out with a group of subjects. In these cases, the sample of subjects should be a model the general population, to which the results of the study will then be applied. Initially, the researcher solves the problem of the size of the experimental sample. Depending on the purpose of the research and the capabilities of the experimenter, it can range from several subjects to several thousand people. The number of subjects in a separate group (experimental or control) varies from 1 to 100 people. For the use of statistical processing methods, the number of subjects in the compared groups is not less than 30–35 people. In addition, it is advisable to increase the number of subjects by at least 5-10% of the required, since some of them or their results will be "rejected" during the experiment.

To form a sample of subjects, several criteria must be taken into account.

1. Substantial. It lies in the fact that the selection of a group of subjects must correspond to the subject and hypothesis of the research. (For example, it makes no sense to recruit two-year-old children into a group of subjects to determine the level of voluntary memorization.) It is desirable to create ideal ideas about the object of experimental research and, when forming a group of subjects, deviate as little as possible from the characteristics of an ideal experimental group.

2. The criterion for the equivalence of the subjects. When forming a group of subjects, one should take into account all the significant characteristics of the research object, the differences in the severity of which can significantly affect the dependent variable.

3. The criterion for representativeness. The group of persons participating in the experiment must represent the entire part of the general population to which the results of the experiment will apply. The size of the experimental sample is determined by the type of statistical measures and the chosen accuracy (reliability) of acceptance or rejection of the experimental hypothesis.

Consider the strategies for selecting subjects from the population.

Random strategy is that each member of the general population is given an equal chance of being included in the experimental sample. To do this, each individual is assigned a number, and then an experimental sample is formed using a table of random numbers. This procedure is difficult to implement, since each representative of the population of interest to the researcher must be taken into account. In addition, the random strategy gives good results when forming a large experimental sample.

Stratometric sampling is used if the experimental sample must necessarily include subjects with a certain set of characteristics (gender, age, level of education, etc.). The sample is made in such a way that the subjects of each stratum (layer) with the given characteristics are equally represented.

Stratometric random sampling combines the two previous strategies. Representatives of each stratum are assigned numbers and an experimental sample is randomly formed from them. This strategy is effective when selecting a small experimental sample.

Representative modeling is used when the researcher manages to create a model of the ideal object of experimental research. The characteristics of a real experimental sample should deviate as little as possible from the characteristics of an ideal experimental sample. If the researcher does not know all the characteristics of the ideal experimental research model, then the strategy is applied approximate simulation. The more accurate the set of criteria describing the population to which the conclusions of the experiment are supposed to be extended, the higher its external validity.

Sometimes as an experimental sample are used real groups, in this case, either volunteers participate in the experiment, or all the subjects are enlisted forcibly. In both cases, external and internal validity is violated.

After the formation of the experimental sample, the experimenter draws up a research plan. Quite often, an experiment is carried out with several groups, experimental and control, which are placed in different conditions. Experimental and control groups should be equivalent at the time of the beginning of the experimental exposure.

The procedure for selecting equivalent groups and subjects is called randomization. According to a number of authors, the equivalence of groups can be achieved when pairwise selection. In this case, the experimental and control groups are composed of individuals equivalent in terms of significant side parameters for the experiment. Ideal for pairwise selection is to attract twin pairs. Randomization with separation of strata consists in the selection of homogeneous subgroups in which the subjects are equalized according to all characteristics, except for additional variables of interest to the researcher. Sometimes, to highlight a significant additional variable, all subjects are tested and ranked according to the level of its severity. The experimental and control groups are formed so that the subjects with the same or similar values ​​of the variable fall into different groups. The distribution of subjects into experimental and control groups can be carried out and by a random method. As mentioned above, with a large experimental sample size, this method gives quite satisfactory results.

4.7. Experimental plans

Experimental plan Is a tactic of experimental research, embodied in a specific system of experiment planning operations. The main criteria for classifying plans are:

The composition of the participants (individual or group);

The number of independent variables and their levels;

Types of scales for representing independent variables;

Experimental data collection method;

Place and conditions of the experiment;

Features of the organization of the experimental impact and the method of control.

Plans for groups of subjects and for one subject. All experimental designs can be divided according to the composition of the participants into designs for groups of subjects and designs for one subject.

Experimenting with group of subjects have the following advantages: the ability to generalize the results of the experiment to the population; the possibility of using schemes of intergroup comparisons; saving time; application of methods of statistical analysis. The disadvantages of this type of experimental plans include: the influence of individual differences between people on the results of the experiment; the problem of representativeness of the experimental sample; the problem of the equivalence of groups of subjects.

Experimenting with one subject- this is a special case of "plans with a small N ". J. Goodwin points out the following reasons for using such plans: the need for individual validity, since in experiments with large N a problem arises when generalized data do not characterize any subject. An experiment with one subject is also carried out in unique cases when, for a number of reasons, it is impossible to attract many participants. In these cases, the goal of the experiment is to analyze unique phenomena and individual characteristics.

The experiment with small N, according to D. Martin, has the following advantages: the absence of complex statistical calculations, ease of interpretation of the results, the ability to study unique cases, the involvement of one or two participants, wide possibilities of manipulating independent variables. It also has some disadvantages, in particular, the complexity of control procedures, difficulty in generalizing the results; relative inefficiency in time.

Consider plans for one subject.

Time series planning. The main indicator of the influence of the independent variable on the dependent in the implementation of such a plan is the change in the nature of the respondent's responses over time. Simplest strategy: schema A- B. The subject initially performs the activity under conditions A, and then under conditions B. To control the "placebo effect", the following scheme is used: A - B - A.(The "placebo effect" is the reactions of the subjects to "empty" stimuli corresponding to the responses to real stimuli.) In this case, the subject does not need to know in advance which of the conditions is "empty" and which is real. However, these schemes do not take into account the interaction of impacts; therefore, when planning time series, as a rule, regular alternation schemes are used (A - B - A- B), positional adjustment (A - B - B- A) or random alternation. The use of longer time series increases the possibility of detecting the effect, but leads to a number of negative consequences - fatigue of the subject, decreased control over other additional variables, etc.

Alternative action plan is a development of the time series plan. Its specificity lies in the fact that the impact A and V are randomly allocated in time and presented to the subject separately. Then the effects of each of the treatments are compared.

Reversible plan is used to study two alternative forms of behavior. Initially, the baseline level of manifestation of both forms of behavior is recorded. Then a complex effect is presented, consisting of a specific component for the first form of behavior and an additional one for the second. After a certain time, the combination of influences is modified. The effect of the two complex impacts is being evaluated.

Criteria ascension plan often used in learning psychology. Its essence lies in the fact that a change in the behavior of the subject is recorded in response to an increase in the impact. In this case, the next impact is presented only after the subject reaches the specified level of the criterion.

When conducting experiments with one subject, it should be borne in mind that the main artifacts are practically unavoidable. In addition, in this case, like in no other, the influence of the experimenter's attitudes and the relations that develop between him and the subject is manifested.

R. Gottsdanker proposes to distinguish qualitative and quantitative experimental designs... V quality In the plans, the independent variable is presented on a nominative scale, that is, in the experiment, two or more qualitatively different conditions are used.

V quantitative In experimental designs, the levels of the independent variable are presented in interval, rank, or proportional scales, i.e., in the experiment, the levels of severity of a particular condition are used.

A situation is possible when, in a factorial experiment, one variable will be presented in a quantitative form, and the other in a qualitative form. In this case, the plan will be combined.

Intragroup and intergroup experimental designs. T.V. Kornilova defines two types of experimental plans according to the criterion of the number of groups and the conditions of the experiment: intragroup and intergroup. TO intragroup refers to designs in which the influence of variants of the independent variable and the measurement of the experimental effect occur in the same group. V intergroup plans, the influence of variants of the independent variable is carried out in different experimental groups.

The advantages of the intragroup design are: fewer participants, elimination of factors of individual differences, a decrease in the total time of the experiment, the possibility of proving the statistical significance of the experimental effect. The disadvantages include the inconstancy of the conditions and the manifestation of the "sequence effect".

The advantages of the intergroup design are: the absence of a "sequence effect", the possibility of obtaining more data, a reduction in the time of participation in the experiment for each subject, a decrease in the effect of dropping out of participants in the experiment. The main disadvantage of the intergroup plan is the inequality of the groups.

Designs with one independent variable and factorial designs. According to the criterion of the number of experimental influences D. Martin proposes to distinguish designs with one independent variable, factorial designs and designs with a series of experiments. In the plans with one independent variable the experimenter manipulates one independent variable, which can have an unlimited number of manifestations. V factorial plans (for more details see p. 120) the experimenter manipulates two or more independent variables, explores all possible options for the interaction of their different levels.

Plans with a series of experiments are carried out to gradually exclude competing hypotheses. At the end of the series, the experimenter comes to the verification of one hypothesis.

Pre-experimental, quasi-experimental designs and true experimental designs. D. Campbell proposed to divide all experimental designs for groups of subjects into the following groups: pre-experimental, quasi-experimental, and true experimental designs. This division is based on the closeness of a real experiment to an ideal one. The fewer artifacts a particular plan provokes and the stricter the control of additional variables, the closer the experiment is to ideal. Pre-experimental designs least of all account for the requirements for an ideal experiment. V.N. Druzhinin points out that they can only serve as an illustration; in the practice of scientific research, they should be avoided whenever possible. Quasi-experimental plans are an attempt to take into account the realities of life when conducting empirical research, they are specially created with a deviation from the schemes of true experiments. The researcher must be aware of the sources of artifacts - external additional variables that he cannot control. A quasi-experimental design is used when the best design is not possible.

Systematized signs of pre-experimental, quasi-experimental designs and true experimental designs are given in the following table.

When describing experimental designs, we will use the symbolization proposed by D. Campbell: R- randomization; X- experimental exposure; O- testing.

TO pre-experimental plans include: 1) the study of a single case; 2) a plan with preliminary and final testing of one group; 3) comparison of statistical groups.

At single case study one group is tested once after experimental exposure. Schematically, this plan can be written as:

Control of external variables and independent variable is completely absent. In such an experiment, there is no material for comparison. The results can be compared only with ordinary ideas about reality, they do not carry scientific information.

Plan with preliminary and final testing of one group often used in sociological, socio-psychological and educational research. It can be written as:

In this regard, there is no control group, so it cannot be argued that changes in the dependent variable (the difference between O1 and O2) recorded during testing are caused precisely by the change in the independent variable. Other "background" events may occur between the initial and final testing, affecting subjects along with the independent variable. This plan also does not allow for the control of the natural development effect and the testing effect.

Comparison of statistical groups more accurately called a plan for two non-equivalent groups with post-exposure testing. It can be written like this:

This plan allows for the effect of testing by introducing a control group to control a number of external variables. However, with its help it is impossible to take into account the effect of natural development, since there is no material for comparing the state of the subjects at the moment with their initial state (preliminary testing was not carried out). To compare the results of the control and experimental groups, Student's t-test is used. However, it should be borne in mind that differences in test results may not be due to experimental exposure, but to differences in the composition of the groups.

Quasi-experimental designs are a kind of compromise between reality and the strict framework of true experiments. There are the following types of quasi-experimental designs in psychological research: 1) experimental designs for non-equivalent groups; 2) plans with preliminary and final testing of various randomized groups; 3) plans of discrete time series.

Plan experiment for non-equivalent groups is aimed at establishing a causal relationship between variables, but it lacks a procedure for equalizing groups (randomization). This plan can be represented by the following diagram:

In this case, two real groups are involved in the experiment. Both groups are being tested. Then one group is experimentally exposed and the other is not. Then both groups are retested. The results of the first and second testing of both groups are compared; for comparison, Student's t-test and analysis of variance are used. Difference O2 and O4 indicates natural development and background exposure. To identify the effect of the independent variable, it is necessary to compare 6 (O1 O2) and 6 (O3 O4), i.e., the magnitude of the indicators' shifts. The significance of the difference in the growth rates will indicate the influence of the independent variable on the dependent variable. This design is similar to that of a true two-group experiment with pre- and post-exposure testing (see p. 118). The main source of artifacts is the difference in the composition of the groups.

Plan with preliminary and final testing of various randomized groups differs from the plan of a true experiment in that one group undergoes preliminary testing, and the final test is an equivalent group that was exposed:

The main drawback of this quasi-experimental design is the inability to control the "background" effect - the influence of events occurring along with the experimental exposure in the period between the first and second testing.

Plans discrete time series are subdivided into several types depending on the number of groups (one or several), as well as depending on the number of experimental impacts (single or series of impacts).

The design of discrete time series for one group of subjects is that the initial level of the dependent variable on the group of subjects is initially determined using a series of successive measurements. Then, an experimental effect is applied and a series of similar measurements is carried out. The levels of the dependent variable are compared before and after exposure. The outline of this plan:

The main disadvantage of a discrete time series design is that it does not provide an opportunity to separate the effect of the independent variable from the effect of background events that occur during the study.

A modification of this design is a time series quasi-experiment in which pre-metering exposure alternates with no pre-metering exposure. Its scheme is as follows:

XO1 - O2XO3 - O4 XO5

The alternation can be regular or random. This option is suitable only if the effect of exposure is reversible. When processing the data obtained in the experiment, the series are divided into two sequences and the results of measurements, where there was an impact, are compared with the results of measurements where it was absent. To compare the data, the Student's t-test with the number of degrees of freedom is used n- 2, where n- the number of situations of the same type.

Time series plans are often put into practice. However, when using them, the so-called "Hotthorn effect" is often observed. It was first discovered by American scientists in 1939, when they conducted research at the Hotthorn plant in Chicago. It was assumed that a change in the system of labor organization would increase its productivity. However, during the experiment, any changes in the organization of labor led to an increase in labor productivity. As a result, it turned out that participation in the experiment itself increased the motivation to work. The subjects realized that they were personally interested, and began to work more productively. To control this effect, a control group should be used.

The scheme of the time series plan for two non-equivalent groups, of which one does not receive impact, looks like this:

O1O2O3O4O5O6O7O8O9O10

O1O2O3O4O5O6O7O8O9O10

This plan allows you to control the "background" effect. It is usually used by researchers when studying real groups in educational institutions, clinics, and in manufacturing.

Another specific plan that is often used in psychology is called an experiment. ex-post-facto. It is often used in sociology, pedagogy, as well as neuropsychology and clinical psychology. The strategy for applying this plan is as follows. The experimenter himself does not influence the subjects. Some real event from their life acts as an impact. The experimental group consists of "subjects" who have been exposed, and the control group consists of people who have not experienced it. In this case, the groups are, if possible, equalized at the time of their state before the impact. Then the dependent variable is tested in representatives of the experimental and control groups. The data obtained as a result of testing are compared and a conclusion is made about the influence of the impact on the further behavior of the subjects. Thus, the plan ex-post-facto simulates the experimental design for two groups with their equalization and testing after exposure. Its scheme is as follows:

If it is possible to achieve equivalence of groups, then this plan becomes the plan of a true experiment. It is being implemented in many modern studies. For example, in the study of post-traumatic stress, when people who have undergone the effects of a natural or man-made disaster, or combatants are tested for the presence of post-traumatic syndrome, their results are compared with the results of the control group, which makes it possible to identify the mechanisms of occurrence of such reactions. In neuropsychology, brain trauma, damage to certain structures, considered as "experimental exposure", provide a unique opportunity to identify the localization of mental functions.

True Experiment Plans for one independent variable differ from the others as follows:

1) using strategies for creating equivalent groups (randomization);

2) the presence of at least one experimental and one control group;

3) final testing and comparison of the results of the groups that received and did not receive the effect.

Let's take a closer look at some experimental designs for one independent variable.

Plan for two randomized groups with post-exposure testing. Its circuit looks like this:

This plan is used if it is not possible or necessary to conduct preliminary testing. If the experimental and control groups are equal, this plan is the best, since it allows you to control most of the sources of artifacts. The absence of preliminary testing excludes both the effect of interaction between the testing procedure and the experimental task, and the effect of testing itself. The plan allows you to control the influence of the composition of the groups, spontaneous elimination, the influence of background and natural development, the interaction of the composition of the group with other factors.

In the considered example, one level of influence of the independent variable was used. If it has several levels, then the number of experimental groups increases to the number of levels of the independent variable.

Plan for two randomized groups with pre-test and post-test. The outline of the plan looks like this:

R O1 X O2

This plan is used when there is doubt about the outcome of randomization. The main source of artifacts is the interaction of testing and experimental impact. In reality, we also have to deal with the effect of non-simultaneous testing. Therefore, it is considered best to conduct testing of members of the experimental and control groups in a random order. The presentation-non-presentation of experimental exposure is also best done at random. D. Campbell notes the need to control "intragroup events". This experimental design has good control over the background effect and the natural development effect.

When processing data, parametric criteria are usually used. t and F(for data in an interval scale). Three values ​​of t are calculated: 1) between O1 and O2; 2) between O3 and O4; 3) between O2 and O4. The hypothesis about the significance of the influence of the independent variable on the dependent variable can be accepted if two conditions are met: 1) the differences between O1 and O2 significant, but between O3 and O4 insignificant and 2) the differences between O2 and O4 significant. Sometimes it is more convenient to compare not absolute values, but the magnitudes of the increase in indicators b (1 2) and b (3 4). These values ​​are also compared using the Student's t-test. If the differences are significant, the experimental hypothesis about the influence of the independent variable on the dependent variable is accepted.

Solomon's plan is a combination of the two previous plans. For its implementation, two experimental (E) and two control (C) groups are required. Its circuit looks like this:

With this plan, the interaction effect of pretesting and the effect of the experimental treatment can be controlled. The effect of the experimental exposure is revealed when comparing the indicators: O1 and O2; O2 and O4; O5 and O6; O5 and O3. Comparison of O6, O1 and O3 reveals the influence of the factor of natural development and background influences on the dependent variable.

Now consider a design for one independent variable and multiple groups.

Design for three randomized groups and three levels of the independent variable it is used in cases where it is necessary to identify quantitative relationships between the independent and dependent variables. Its circuit looks like this:

In implementing this plan, each group is presented with only one level of the independent variable. If necessary, you can increase the number of treatment groups in accordance with the number of levels of the independent variable. All of the above statistical methods can be used to process the data obtained using such an experimental design.

Factorial Experimental Designs are used to test complex hypotheses about the relationships between variables. In a factorial experiment, as a rule, two types of hypotheses are tested: 1) hypotheses about the separate influence of each of the independent variables; 2) hypotheses about the interaction of variables. The factorial design is for all levels of the explanatory variables to fit together. The number of experimental groups is equal to the number of combinations.

Factorial design for two independent variables and two levels (2 x 2). This is the simplest of the factorial designs. His diagram looks like this.

This design reveals the effect of two independent variables on one dependent. The experimenter combines possible variables and levels. Sometimes, four independent, randomized experimental groups are used. Fischer analysis of variance is used to process the results.

There are more complex versions of the factorial design: 3 x 2 and 3 x 3, etc. Addition of an independent variable to each level increases the number of experimental groups.

"Latin square". It is a simplification of the full design for three independent variables of two or more levels. The principle of the Latin square is that two levels of different variables meet experimentally only once. This significantly reduces the number of groups and the experimental sample as a whole.

For example, for three independent variables (L, M, N) with three levels each (1, 2, 3 and N (A, B, C)) the plan according to the "Latin square" method will look like this.

In this case, the level of the third independent variable is (A, B, C) occurs in each line and in each column once. By combining the results by rows, columns and levels, it is possible to reveal the influence of each of the independent variables on the dependent, as well as the degree of pairwise interaction of the variables. The use of Latin letters A, B, WITH to designate the levels of the third variable is traditional, therefore the method was called "Latin square".

"Greco-Latin square". This design is used when it is necessary to investigate the influence of four independent variables. It is built on the basis of a Latin square for three variables, with a Greek letter attached to each Latin group of the plan, denoting the levels of the fourth variable. The schema for a plan with four independent variables, each with three levels, would look like this:

To process the data obtained in the "Greco-Latin square" plan, the Fischer analysis of variance is used.

The main problem that factorial designs can solve is determining the interaction of two or more variables. This problem cannot be solved by applying several routine experiments with one independent variable. In terms of factor, instead of trying to “cleanse” the experimental situation of additional variables (with a threat to external validity), the experimenter brings it closer to reality by introducing some additional variables into the category of independent ones. At the same time, the analysis of the relationships between the studied characteristics allows us to reveal the hidden structural factors, on which the parameters of the measured variable depend.

4.8. Correlation studies

The theory of correlation research was developed by the English mathematician K. Pearson. The strategy for conducting such a study is that there is no controlled impact on the object. The correlation study plan is simple. The researcher puts forward a hypothesis about the presence of a statistical relationship between several mental properties of an individual. In this case, the assumption of a causal relationship is not discussed.

Correlation is a study conducted to confirm or disprove the hypothesis of a statistical relationship between several (two or more) variables. In psychology, mental properties, processes, states, etc., can act as variables.

Correlation links."Correlation" literally means ratio. If a change in one variable is accompanied by a change in another, then one speaks of the correlation of these variables. The presence of a correlation between two variables is not evidence of a causal relationship between them, but makes it possible to put forward such a hypothesis. The lack of correlation allows us to refute the hypothesis of a causal relationship of variables.

There are several types of correlations:

Direct correlation (the level of one variable directly corresponds to the level of another variable);

Correlation due to the third variable (the level of one variable corresponds to the level of the other variable due to the fact that both of these variables are due to a third, common variable);

Random correlation (not driven by any variable);

Correlation due to the heterogeneity of the sample (if the sample consists of two heterogeneous groups, then a correlation can be obtained that does not exist in the general population).

Correlation links are of the following types:

- positive correlation (an increase in the level of one variable is accompanied by an increase in the level of another variable);

- negative correlation (an increase in the level of one variable is accompanied by a decrease in the level of another);

- zero correlation (indicates the absence of a relationship between variables);

- nonlinear relationship (within certain limits, an increase in the level of one variable is accompanied by an increase in the level of another, and with other parameters - vice versa. Most psychological variables have a nonlinear relationship).

Planning a correlation study. The correlation study design is a kind of quasi-experimental design in the absence of the influence of the independent variable on the dependent. The correlation study is divided into a series of independent measurements in a group of subjects. When simple correlation study group is homogeneous. When comparative correlation research, we have several subgroups that differ in one or more criteria. The results of such measurements give a matrix of the form R x O. The data of a correlation study are processed by calculating correlations by rows or by columns of a matrix. Row correlation gives comparison of subjects. Column correlation provides information about the relationship of measured variables. Temporal correlations are often identified, i.e., changes in the structure of correlations over time.

The main types of correlation research are discussed below.

Comparison of the two groups. It is used to establish the similarity or difference between two natural or randomized groups in terms of the severity of one or another parameter. The mean results of the two groups are compared using the Student's t-test. If necessary, Fisher's t-test can also be used to compare the variances of an indicator in two groups (see 7.3).

One-dimensional study of one group in different conditions. The design of this study is close to experimental. But in the case of a correlation study, we do not control the independent variable, but only state the change in the behavior of the individual under different conditions.

Correlation study of pairwise equivalent groups. This design is used in the study of twins using the intra-pair correlation method. The twin method is based on the following provisions: the genotypes of monozygotic twins are 100% similar, and dizygotic twins - by 50%, the development environment for both dizygotic and monozygotic pairs is the same. Dizygotic and monozygotic twins are divided into groups: each contains one twin from a pair. In twins of both groups, the parameter of interest to the researcher is measured. Then the correlations between the parameters are calculated (O-correlation) and between twins (R-correlation). By comparing the intrapair correlations of monozygotic and dizygotic twins, it is possible to reveal the proportion of the influence of the environment and genotype on the development of a particular trait. If the correlation of monozygotic twins is reliably higher than the correlation of dizygotic twins, then we can talk about the existing genetic determination of the trait, otherwise we talk about environmental determination.

Multivariate correlation study. It is carried out to test the hypothesis about the relationship of several variables. An experimental group is selected, which is tested according to a specific program, consisting of several tests. The research data is entered into the raw data table. Then this table is processed, the linear correlation coefficients are calculated. Correlations are assessed for statistical differences.

Structural correlation study. The researcher reveals the difference in the level of correlation dependences between the same indicators measured in representatives of different groups.

Longitudinal correlation study. It is built according to a time series plan with group testing at specified intervals. In contrast to a simple longitude, the researcher is interested not so much in the changes of the variables themselves as in the relationships between them.

About psychology through the purposeful intervention of the researcher in the life of the subject.

Various authors interpret the concept of "psychological experiment" ambiguously, often under an experiment in psychology a complex of different independent empirical methods is considered ( the experiment itself, observation, survey, testing). However, traditionally in experimental psychology, an experiment is considered an independent method.

Psychological experiment (within the framework of psychological counseling)- a specially created situation, designed for a more holistic (in various modalities) experience of the client's own experience.

The specifics of a psychological experiment

In psychology, experimental research has its own specifics, allowing it to be considered separately from research in other sciences. The specificity of a psychological experiment is that:

• The psyche as a construct cannot be objectively observed and its activity can be learned only based on its manifestations, for example, in the form of a certain behavior.
• When studying mental processes, it is considered impossible to single out any one of them, and the impact always occurs on the psyche as a whole (or, from a modern point of view, on the body as a single indivisible system).
• In experiments with humans (as well as some higher animals, for example, primates), there is an active interaction between the experimenter and the subject.
• This interaction, among other things, makes it necessary for the subject to have instructions (which, obviously, is not typical for natural science experiments).

General information

In a simplified example, the independent variable can be viewed as a relevant incentive (St (r)), the strength of which varies by the experimenter, while the dependent variable is the reaction ( R) of the subject, his psyche ( P) on the impact of this relevant stimulus.

However, as a rule, it is precisely the sought-for stability of all conditions, except for the independent variable, that is unattainable in a psychological experiment, since in addition to these two variables, there are almost always additional variables, systematic irrelevant incentives (St (1)) and random stimuli ( St (2)), leading to systematic and random errors, respectively. Thus, the final schematic representation of the experimental process looks like this:

Therefore, in the experiment, three types of variables can be distinguished:

1. Additional variables (or external variables)

So, the experimenter is trying to establish a functional relationship between the dependent and independent variable, which is expressed in the function R= f ( St (r)), while trying to take into account the systematic error that arose as a result of the influence of irrelevant stimuli (examples of systematic error can be called the phases of the moon, time of day, etc.). To reduce the likelihood of the impact of random errors on the result, the researcher strives to conduct a series of experiments (an example of a random error, for example, fatigue or a speck in the subject's eye).

The main objective of the experimental study

The general purpose of psychological experiments is to establish the presence of a connection R= f ( S, P) and, if possible, the type of function f (there are various types of relationships - causal, functional, correlation, etc.). In this case, R- the reaction of the subject, S- the situation, and P- the personality of the subject, psyche, or "internal processes". That is, roughly speaking, since it is impossible to "see" mental processes, in a psychological experiment, based on the reaction of the subjects to the stimulation regulated by the experimenter, some conclusion is made about the psyche, mental processes or personality of the subject.

Experiment stages... In each experiment, the following stages can be distinguished. The first stage is the formulation of the problem and the goal, as well as the construction of the experiment plan. The experiment plan should be built taking into account the accumulated knowledge and reflect the urgency of the problem. The second stage is the actual process of actively influencing the surrounding world, as a result of which objective scientific facts accumulate. The obtaining of these facts is largely facilitated by a correctly selected experimental technique. As a rule, the experimental method is formed on the basis of the difficulties that must be eliminated in order to solve the problems posed in the experiment. The technique developed for some experiment may turn out to be suitable for other experiments, that is, acquire a universal value.

Validity in a psychological experiment

As in natural science experiments, so in psychological experiments, the concept of validity is considered the cornerstone: if the experiment is valid, scientists can have some confidence that they have measured exactly what they wanted to measure. Many steps are taken to ensure that all types of validity are met. However, it is impossible to be absolutely sure that in some, even the most thoughtful, research it is possible to completely comply with all the criteria of validity. A completely flawless experiment is unattainable.

Experiment classifications

Depending on the method of conducting

There are mainly three types of experiments:

• Formative, or psychological and pedagogical experiment The introduction of this type into this classification violates the rules for constructing a classification. First, each object (in this case, research) can be attributed to only one type. However, a formative experiment can be both laboratory and natural. For example, the experiments of I.P. Pavlov on the development of conditioned reflexes in dogs are a laboratory formative experiment, and experiments within the framework of the theory of developmental learning by Elkonin and Davydov are mainly field formative experiments. Secondly, the classification should have only one basis, that is, the species are divided according to one characteristic. However, according to such a criterion as a method of carrying out or conditions of carrying out, only laboratory and field experiments can be distinguished, and a formative experiment is distinguished according to a different criterion.

Depending on the conditions of the conduct

• Laboratory experiment - conditions are specially organized by the experimenter. The main task is to ensure high internal validity. The allocation of a single independent variable is characteristic. The main way to control external variables is elimination (elimination). The external validity is lower than in the field experiment.
• Field, or natural experiment - an experiment is carried out under conditions that the experimenter does not control. The main task is to ensure high external validity. Isolation of a complex independent variable is characteristic. The main ways to control external variables are randomization (the levels of external variables in the study exactly correspond to the levels of these variables in life, that is, outside the study) and constancy (to make the level of the variable the same for all participants). Internal validity is generally lower than in laboratory experiments.

Depending on the result of the impact, they emit

Ascertaining experiment - the experimenter does not irreversibly change the participant's properties, does not form new properties in him and does not develop those that already exist.

Formative experiment - the experimenter changes the participant irreversibly, forms in him such properties that did not exist before, or develops those that already existed.

Depending on the stage of the study

• Pilot study (the so-called rough, pilot study)
• The experiment itself

Depending on the level of awareness

Depending on the level of awareness, experiments can also be divided into

• those in which the subject is given complete information about the goals and objectives of the research,
• those in which, for the purpose of the experiment, some information about him from the subject is concealed or distorted (for example, when it is necessary that the subject does not know about the true hypothesis of the research, he may be told a false one),
• and those in which the subject is not aware of the purpose of the experiment or even the very fact of the experiment (for example, experiments involving children).

Organization of the experiment

A flawless experiment

No experiment in any science is capable of withstanding the criticism of advocates of "absolute" accuracy of scientific conclusions. However, as a standard of perfection, Robert Gottsdanker introduced into experimental psychology the concept of "perfect experiment" - an unattainable ideal of an experiment that fully satisfies three criteria (ideality, infinity, full compliance), which researchers should strive to approach.

Interaction between experimenter and subject

The problem of organizing the interaction between the experimenter and the subject is considered one of the main ones generated by the specifics of psychological science. Instructions are considered as the most common means of direct communication between the experimenter and the subject.

Instructions to the test subject

The instruction to the subject in a psychological experiment is given in order to increase the likelihood that the subject adequately understood the experimenter's requirements, therefore, it gives clear information about how the subject should behave, what he is asked to do. For all subjects within the same experiment, the same (or equivalent) text with the same requirements is given. However, due to the individuality of each subject, in experiments the psychologist is faced with the task of ensuring an adequate understanding of the instructions by a person. Examples of differences between subjects that determine the appropriateness of an individual approach:

• some subjects only need to read the instructions once, others - several times,
• some subjects are nervous, while others remain cold-blooded,
• etc.

Requirements for most instructions:

• The instruction should explain the purpose and significance of the study.
• She clearly state the content, course and details of the experience
• It should be detailed and at the same time rather laconic.

Sampling problem

Another challenge facing the researcher is sampling. The researcher must first of all determine its volume (number of subjects) and composition, while the sample must be representative, that is, the researcher must be able to extend the conclusions drawn from the results of the study of this sample to the entire general population from which this sample was collected. For these purposes, there are various strategies for selecting samples and forming groups of subjects. Very often, for simple (one-factor) experiments, two groups are formed - control and experimental. In some situations, it can be quite difficult to select a group of subjects without creating a selection bias.

Stages of a psychological experiment

The general model for conducting a psychological experiment meets the requirements of the scientific method. When conducting a holistic experimental study, the following stages are distinguished:

1. Primary problem statement
   • Formulation of a psychological hypothesis
2. Working with scientific literature
   • Finding definitions of basic concepts
   • Compilation of a bibliography on research topics
3. Refinement of the hypothesis and definition of variables
   • Defining an experimental hypothesis
4. Choosing an experimental tool that allows you to:
   • Control the independent variable
   • Register dependent variable
5. Pilot Study Planning
   • Highlighting additional variables
   • Choosing an experimental plan
6. Sampling and distribution of subjects into groups in accordance with the adopted plan
7. Experimenting
   • Preparing an experiment
   • Instructing and motivating subjects
   • Experimenting itself
8. Primary data processing
   • Compilation of tables
   • Information form transformation
   • Data validation
9. Statistical processing
   • Choice of statistical processing methods
   • Converting an experimental hypothesis to a statistical hypothesis
   • Statistical processing
10. Interpretation of results and conclusions
11. Fixation of the research in a scientific report, article, monograph, letter to the editorial office of a scientific journal

The advantages of experiment as a research method

The following main advantages of the experimental method in psychological research can be distinguished:

• Possibility to choose the moment of the beginning of the event
• Recurrence of the event under study
• Variability of Results by Deliberate Manipulation of Independent Variables

Control methods

1. Exclusion method (if a certain feature is known - an additional variable, then it can be excluded).
2. Equalization method (used when one or another interfering feature is known, but cannot be avoided).
3. Randomization method (used if the influencing factor is not known and it is impossible to avoid its impact). A method of rechecking a hypothesis on different samples, in different places, on different categories of people, etc.

Criticism of the experimental method

Proponents of the inadmissibility of the experimental method in psychology rely on the following provisions:

• Subject-Subject Relationship Breaks Scientific Rules
• The psyche has the property of spontaneity
• The psyche is too fickle
• The psyche is too unique
• The psyche is too complex an object of study
• And etc.

Notable psychological experiments

• Zarochentsev K. D., Khudyakov A. I. Experimental psychology: textbook. - M .: Publishing house Prospect, 2005. ISBN 5-98032-770-3
• Research in psychology: methods and planning / J. Goodwin. - 3rd ed. - SPb .: Peter, 2004. ISBN 5-94723-290-1
• Martin D. Psychological experiments. SPb .: Prime-Evroznak, 2004. ISBN 5-93878-136-1
• Nikandrov V.V. Observation and experiment in psychology. SPb .: Rech, 2002 ISBN 5-9268-0141-9
• Solso R.L., Johnson H.H., Beale M.K. Experimental Psychology: A Practical Course. - SPb .: Prime-EVROZNAK, 2001.
• Gottsdanker, Robert;"Foundations of a psychological experiment"; Publishing house: M .: Moscow State University, 1982;
• D. Campbell. Experimental models in social psychology and applied research. M., Progress 1980.

Science develops according to certain laws. The main thing for science is the method of cognition, its reliability and objectivity. Scientists try to operate with proven facts and strive to clearly record the difference between facts and hypotheses. People outside of science often confuse scientific fact and speculation; often take what is desired or imagined for what really exists in nature. Before conducting a study, scientists always formulate some scientific problems in the form of contradictions between what we know and what we do not know, as well as what we may learn after planned research. In addition, scientists are also required to justify relevance and novelty his research. Of course, the scientific experimental method is not perfect and cannot be infallible. However, it is many orders of magnitude more accurate than the usual perception and sensations of a person, given to him by nature and "formatted" by a social environment operating with social ideas, myths, stereotypes, prejudices, etc.

As already noted, the basic principles of all experimental sciences at the beginning of the 17th century. formulated by Galileo Galilei. He showed that the main method of scientific cognition is experiment, and the scientific explanation of the studied world should be based on a theory or model describing a certain ideal object, containing the main characteristics of the studied real objects and, as it were, excluding all secondary and inessential. Moreover, ideal objects do not exist in nature; they are present only in the thinking of a scientist, in scientific literature and are the result of scientific activity describing in a generalized form the basic properties of all real objects of a given type.

Table 3.1

Comparative table of the main types of scales and mathematical criteria for processing the results

(according to N.K. Malhotra)

	Main characteristics	Well-known examples	Examples from marketing	Statistics
				descriptive	deductive
Memorial (non-metric)	Numbers designate and classify objects	Health insurance numbers, soccer team numbers	Brand numbers, stores, gender classification	Percentage relationships, fashion	Chi-square test, binomial test
Ordinal (non-metric)	The numbers indicate the relative positions of objects, but not the magnitude of the differences between them.	Quality ranks, team ranks in competition, ratings	Preference ranks, market position, social class	Percentiles, median	Rank correlation, analysis of variance
Interval (metric)	The difference between the objects being compared. The starting point is freely selectable	Temperature (Fahrenheit, Celsius)	Relationships, opinions, odds	Range, mean, standard deviation	Correlation coefficient, t -criterion, regression, factor analysis, analysis of variance
Relative (metric)	The reference point is fixed. Coefficients can be calculated by the supplied scale	Length, width, height, weight	Age, income, costs, sales volumes, market shares	Geometric mean, harmonic mean	The coefficient of variation

The main method of psychology is experiment, which is a type of empirical research, in the process of which it is checked scientific hypothesis and the causal relationships between the variables are identified. Unlike correlation research, where the statistical relationships between the variables and the factors influencing them are established, in the experiment we get the opportunity to find the reason phenomena, and analyzing the sequence of causes and effects hidden from us, describe it internal mechanism. Moreover, if the volume of possible causes is large enough, then the formulation of the reason chosen by the researcher from a possible set can be arbitrary, or rather, related to the tasks that the author solves within the framework of his research activity.

From observation the experiment differs in that it involves the active intervention of the researcher in the situation of the research. While performing an experiment, the researcher controls (manipulates) one or more variables and records all changes that occur during the experiment. He studies the influence independent variable(initial data) on dependent variables(observed results).

In psychology, as in many other sciences, experiments of several types are carried out. In social psychology, the type of research with experimental and control groups of subjects. However, in psychology, situations may arise when it is extremely difficult or even impossible to conduct an experiment for a number of reasons, for example, due to the fact that, once participating in an experiment, a person unwittingly learns, and this affects the repeated performance of the experimental task. Under the experimental conditions, the subject can have different motivation - both very high and very low or inadequate to the experimental conditions, which can also significantly affect the results. The subject often seeks to impress the experimenter, or vice versa, the experimenter may cause him a negative attitude. Or, for example, the subject can emotionally react to the task, experience anxiety, embarrassment, and other emotions. All these artifacts are taken into account during the experiment, if, of course, they can in principle be taken into account.

One of the main criteria for the scientific nature and reliability of a laboratory experiment is its reproducibility in similar laboratory conditions. Another criterion is mandatory statistical processing the results obtained, i.e. application of mathematics.

Method natural experiment was first proposed by the Russian psychologist A. F. Lazursky in 1910. A natural experiment provides reliable information, but cannot be performed repeatedly, since the subjects know about it and behave in such a way that the experimenter often cannot control the research situation. Ethical problems often arise when conducting psychological experiments. For example, the question of how ethical it is to use covert observation, covert video and audio recording equipment, Gesell's mirrors, etc. is widely discussed. Very often, the outstanding American experimental psychologist Stanley Milgram was accused of unethical research.

The history of psychology knows many talented scientists who were engaged in experimental research in its various branches and developed not only methods for studying certain phenomena and causes that cause them, but also formulated general principles and requirements for the development and conduct of experiments. It is impossible to list their names. Suffice it to recall the most striking names that significantly advanced psychology in terms of its understanding of the nature of the human psyche and communication. They are S. Milgram, M. Sheriff, S. Ash, E. Mayo, L. Festinger, S. Moskovichi, F. Zimbardo, E. L. Thorndike, B. F. Skinner, W. Neisser, K. Koffka, F. Keller, M. Wertheimer, K. Levin, D. Kahneman and A. Tversky and many, many others.

Most often in psychology, they distinguish laboratory experiments and field, i.e. in vivo. Laboratory experiments are conducted in isolated conditions and often using special equipment and instrumentation. These two types of experiments differ in a number of characteristics, but in all cases they give the most complete understanding of the nature of certain phenomena, objects, processes, etc., allow to reveal hidden sequences of cause-and-effect relationships (mechanisms) of the observed phenomena.

Conducting experiments involves the allocation of units of measurement, variables, the use of certain experimental designs, etc. In psychology units of observation, as a rule, people who are called test subjects (in applied sociology, the term "respondents" is used), In experiments, independent and dependent variables are distinguished. Dependent variables characterize the degree of influence of independent variables controlled by the researcher. Independent variables include the results of the actions performed by the subjects, solving problems, etc. All people who can be recruited as potential subjects in the study are called general population. Any of the groups that make up the general population and take part in the study is called sampling. Since conclusions based on the results of sample studies are made about the entire general population of subjects, and not just about the sample, it is important that it reflects the properties of the entire target group. If this can be observed, then the sample is called representative, if not, then - unrepresentative .

When conducting experiments by the method of the control and experimental groups, the process of distributing the subjects into groups is very important. When randomly assigned (randomization), each selected participant has an equal chance of getting into any of the groups (experimental or control). As a result, the task of the second stage of the formation of the control and experimental groups is to distribute the subjects with individual differences as evenly as possible over the two groups, i.e. equalize the groups or make them equivalent (for example, by gender, age, income level, etc.).

When conducting experiments, it is also necessary to take into account the factors of the psychic dynamics of the subjects, since after time, from one measurement to another, the subjects gain experience, get tired, change their attitude to the task, and in longitudinal (long-term) research - they get old, change their stable views and can even change their worldview.

For schematization of experimental plans, the following designations are adopted:

X - the effect of the independent variable, the result of which is to be assessed;

O - the process of observation and measurement of the dependent variable;

R - randomization - random order of presentation of stimuli or distribution of subjects into groups in a random order.

In addition, movement from left to right in the experimental plan means movement in time. The horizontal arrangement of symbols in the formula means that they belong to the same sample; the vertical arrangement of the symbols means that they refer to events that occur simultaneously.

Example 1

X O1 O2

This order of the symbols means that one group of subjects was exposed to some independent factor (X) and the response to it was measured two times - O1 and O2.

Example 2

R X О1

R X O2

The record means that two groups of subjects were formed simultaneously on the basis of a random distribution ( R ). Then the subjects were exposed to some independent factor (X), and the response to it was determined in both groups at the same time point - O1 and O2 .

Example 3

EU: R О1 X О1

CG: R O3 O4

This is an experimental model in which the experimental group ( EG ) is influenced by an independent factor, and the control ( CG ) is not exposed. Preliminary and final measurements are carried out in both groups. The sample of respondents is determined randomly ( R ), in this case, half of the subjects are selected for inclusion in the experimental group ( EG ), half - to the control ( CG ). After that, a certain state of the respondents of both groups is recorded, for example, with the help of measuring equipment or by filling out a special test (O1 and O3). Then the members of the experimental group are influenced (for example, they are shown some object for perception, they solve some kind of mental problem, or they watch an advertising video, which should cause motivation to buy a product). After that, the members of both groups are again subjected to examination (O2 and O4) . The experimental effect is defined as

(O2-O1) - (O4-O3).

This experimental design allows you to control a large number of extraneous factors. But another plan for conducting the experiment is also possible, for example, when the experimental group of respondents is exposed, and the control group is not exposed, but preliminary measurements are not carried out.

Example 4

EG: K X О1

CG: R O 2

Here the effect of the experimental action is calculated as

This model is very easy to use, however, with this technique, the results of the experiment can be influenced by extraneous factors (artifacts). Due to the fact that this model is easier for the researcher (in terms of timing, cost, sample size, etc.), it is most common both in psychology and in a number of other experimental sciences.

If the researcher, for some reason, cannot use the models described above a valid experiment, he resorts to pseudo-experiment. In this case, it is necessary to take into account the influence of uncontrollable factors on the results obtained, since the level of control of conditions in such an experiment is much lower than in studies performed according to the plan of an actual experiment. The most common examples of pseudo-experimentation are time series and multiple time series.

Time series Is a model that periodically measures dependent variables. The measurement of the variable is carried out both before and after the exposure, which makes it possible to assess the degree of influence of the independent factor.

Example 5

O 1 O 2 O 3 O 4 X O 6 O 7 O 8 O 9

This model can be illustrated as follows. In the group of subjects at each moment of time (day, week, etc.), for a certain period of time, a certain characteristic is fixed, for example, the number of loans issued by the bike ( O 1, O 2, O 3, O 4). Then carried out

advertising or PR campaign of the bank ( X ), after which the dynamics of issued loans (O5, O6, O7, O8) is again monitored by similar time parameters . Customer activity is recorded both before and after the promotion, which allows you to determine whether the impact of the advertising campaign has a short-term, long-term or no impact on customer behavior. The main disadvantage of such an experimental design is the inability to separate the influence of a certain factor from any other factors (artifacts) that can influence in a latent form during the entire study on its results.

Multiple Time Series Model is an experimental design, similar in content to the time series model, but it uses not only the experimental, but also the control group.

Example 7

O 1 O 2 O 3 O 4 O 5 X O 6 O 7 O 8 O 9 O 10

O 1" O 2" O 3" O 4" O 5" O 6" O 7" O 8" O 9" O 10"

This model gives more reliable results, with the reliability of the study increased by comparing the results of measurements in groups. In the experimental group, the results are compared before and after exposure to the independent variable and with the control group.

• As a fundamental science, psychology was formed about 250 years after the death of Galileo, when, as mentioned above, the German psychologist Wilhelm Wundt created the world's first experimental psychological laboratory and began an experimental study of the structure of the psyche.
• Methodologists include the periodic table, the law of an ideal gas, some mathematical concepts (point, line, plane), etc.
• For example, participants in a single focus group study in marketing may be a non-representative sample, while participants in a mass survey may be a representative sample. Therefore, in order to obtain more accurate data, several focus group studies are carried out, comparing the obtained qualitative results with quantitative ones (mass surveys).

Experiment is a method of collecting facts in specially created conditions that ensure the active manifestation of the studied mental phenomena. The experiment involves the active intervention of the researcher in the activity of the subject in order to create conditions in which a psychological fact is revealed. It is designed to identify causal relationships or developmental determinants.

The specifics of the experiment method:

1. The active position of the researcher. The researcher can call a mental phenomenon as many times as necessary to test the hypothesis put forward.

2. Creation of a previously thought out artificially created situation in which the studied property manifests itself best and it can be more accurately and easily determined.

3. In experimental studies, it is important that all subjects are equal in age, health, motives for participation, etc. The motives for participation vary only when it is precisely their influence on a particular mental phenomenon that is studied.

4. The reliability of the hypothesis being tested is achieved either by repeated repetition of experiments, or due to a sufficient number of subjects with subsequent mathematical processing.

5. The results of each experiment are recorded in a protocol, where general information about the subjects is recorded, the nature of the experimental task, the time of the experiment, the quantitative and qualitative results of the experiment, the characteristics of the subjects: actions, speech, expressive movements, etc.

6. When experimenting with children, it is very important to keep in mind that the child may perceive the problem not as it was formulated, but in a different way.

Types of variables in experimental studies:

Independent variable - A factor that is changed by the experimenter.

The dependent variable is a factor that changes under the influence of another factor.

The researcher deliberately creates and changes the conditions in which human activity takes place, sets tasks and, based on the results, judges the psychological characteristics of the subject. An experiment tests a hypothesis or assumption about the relationship of variables. The method assumes control of variables, selection of dependent and independent variables (to establish causal relationships) and comparison of the results of solving problems of the experimental (in which the value of the variable varies) and control (variables remain unchanged) groups. The experiment involves two measurements - pretest (before changing the variable) and posttest (after changing).

Experiment types:

one). Laboratory experiment - is carried out in deliberately created conditions (specially equipped room), using the means of recording the received data, the actions of the subject are determined by the instruction.

- using hardware

- without using equipment

Laboratory experiment
1.Peculiarities of activity and behavior are registered: actions, actions, their components. 2. Reactions and their components: motor, speech, vegetative. 3. Electrical activity: brain, muscles, skin, heart.	Requirements 1. Positive, responsible attitude of the subject to the experiment. 2. Equality of motives and conditions for participation in the experience of all subjects. 3.Clear unambiguous instructions before the experiment, understandable to the subject. 4. Strict consideration of subjective factors: emotional state, fatigue, etc. 5. A sufficient number of subjects and the number of experiments (series).
Advantages 1. The ability to create conditions that cause the necessary mental process. 2. Possibility of strict accounting for the measurement of stimuli and responses. 3. Possibility of repeating experiments. 4. Possibility of mathematical processing.	Disadvantages 1. Possibility of distorting the natural course of the mental process. 2. Although the presence of a laboratory is not necessary, the subject knows that he is being experimented on.

2). Natural experiment - organized and carried out in ordinary life conditions, where the experimenter hardly interferes with the course of the events taking place, fixing them in the form as they unfold by themselves. The researcher, before starting his work, gets to know children, takes an active part in their life, therefore, the classes conducted by the experimenter do not cause alertness.

- psychological and pedagogical experiment (evaluates the developmental effect of training programs and influences)

- other types depending on the field of psychology

Benefits of Natural Experiment:

1. The activity of the subjects is studied in natural conditions.

2. The researcher himself actively induces mental processes in connection with the task:

Changes the conditions of activity;

Changes the phenomenon being studied;

Repeats the studied phenomenon.

3. Accumulated facts can be mathematically processed. The reliability of objectively obtained results is increased.

3). The ascertaining experiment - establishes the actual state and level of certain features of mental development (level or quality) at the time of the experiment. An example of an ascertaining experiment can be a test examination of the intelligence of children, carried out using various methods.

4). Formative experiment - its intention is to artificially recreate (simulate) the process of mental development. The goal is to study the conditions and patterns of origin of a particular mental neoplasm. Active formation of the studied property (according to the hypothesis) in the process of specially organized experimental training and education. The task is to form a new ability for the subject. The researcher theoretically outlines and empirically selects suitable ways and means to achieve the desired result, trying to achieve the "planned" indicators of the formation of the ability. The formation of the ability of attention in younger schoolchildren as an action of internal control (P.Ya. Galperin) became textbook examples of the implementation of a formative experiment.

Requirements for a formative experiment:

1). Development of theoretical ideas about the parameters of formed mental phenomena.

2). Clarity of planning the experiment.

3). Completeness of accounting for various factors of real learning that affect the emergence of the studied mental phenomena.

The specifics of the formative experiment:

The main object of study is the formative activity of the child.

Learning is structured by the consistent introduction of more and more new tools that help to include the child in cognitive activity.

The design of educational programs and their approbation are carried out in the form of tests of well-thought-out hypotheses.

The organization and implementation of such a formative experiment requires interdisciplinary collaboration (philosophers, sociologists, logicians, educators, psychologists, physiologists).

- teaching experiment- teaching any knowledge, skills, skills;

- educational experiment - carries out the formation of certain personality traits.

In addition to the main methods of empirical research, a number of additional ones can be distinguished. Auxiliary research methods are usually used in combination. First of all, this is the clarification of knowledge, opinions, ideas, attitudes, etc. on a wide range of questions of people of different age categories using the methods of conversation, survey, testing, etc.

Polling method.

Polling is a method in use that a person answers a series of questions asked.

When applying the survey method, difficulties may arise due to the fact that the child does not always correctly understand the questions addressed to him. This is due to the fact that the system of concepts that controls this process may face the illusion of imaginary understanding, which consists in the fact that the child intelligently answers the questions posed to him, but in reality puts them in a slightly different meaning than the adult asking the questions.

There are topics that cause negative feelings in the child, which he prefers not to touch.