BSPU them. M. Tanka

Institute of Psychology

EXPERIMENTAL PSYCHOLOGY

Compiler Radchikova Natalia Pavlovna

In his professional activity, a psychologist must not only have a good command of the theoretical issues of special subjects, but also see the expediency and effectiveness of applying certain methods of experimental research in practice. Such techniques form the basis of scientific psychological explanation and the scientific method of accumulating psychological knowledge.

While experimental methods are becoming widespread in the field of psychological research, there is a growing need for their methodological support - the organization of a “correct” experiment. Therefore, the course "Experimental Psychology" is focused, on the one hand, on the methodological preparation of students for conducting various kinds of experimental research, and, on the other hand, on providing students with the necessary recommendations for writing upcoming term papers and theses.

The main objectives of this course are

1) in ensuring the proper level of training of future psychologists in the direction of the theory and methodology of research in the field of psychology;

2) in developing in them the necessary skills in the practical conduct of experimental work;

3) in developing the ability to navigate in specialized literature and critically analyze the material read, especially the materials of experimental studies.

Course objectives:

* give the basic concepts and definitions adopted in the field of experimental psychology;

* consistently acquaint students with all stages of the experiment - from the birth of an idea and the formation of a testable hypothesis to the presentation of the results of their work;

* to familiarize students with the basic schemes and modern methods of conducting experiments;

* analyze possible errors, difficulties, advantages and disadvantages of the discussed experimental schemes;

* to prepare students for conducting independent experimental psychological research.

COURSE PROGRAM

1. Philosophical foundations of experimental psychology. Knowledge. The difference between scientific knowledge and other forms of knowledge. Types of beliefs. The nature of scientific explanation. Rationalism. Empiricism. Critical thinking. Falsification. intermediate variables. Approaches to the evaluation of scientific theories.

2. Introduction to experimental psychology. How to start psychological research. Introduction. The role and place of experimental psychology. Goals and objectives of the course in experimental psychology. Course content. Goals and objectives of psychological research. Experiment. The concept of experiment. The difference between the experiment and other types of empirical research. The concept of a variable. The structure of the experiment. Dependent, independent and control variables. Mixing effect. Pilot research project. Pilot project stages. Sources of ideas. Development of testable hypotheses. Literature analysis. Development of the scheme of the experiment. Null hypothesis. Pilot studies. Data collection. The concept of statistical data analysis. The level of statistical significance. Interpretation of results. Preparation of a pilot report.

3. Observations in psychological research. The role of observations in psychology. Main types of observations. Validity: external validity, internal validity, construct validity. The main sources of violation and ways to increase validity. Descriptive observations: naturalistic, special cases (precedents), reviews. - features, main advantages and disadvantages. dependent observations. The concept of correlation. correlation technique. Correlation coefficient. Interpretation of the correlation coefficient. Problems in the interpretation of the correlation coefficient. Mixing. Limited data interval. Causal observations. Experiment. Benefits of experimental observations. Ways to improve the reliability of observations. Instructions. protocols. Equipment used in experimental psychological research.

4. Measurements in psychological research. Measuring scales in psychology. The concept of a scale. Types of measuring scales. Naming scale (nominative scale). Order scale (ordinal scale). Interval scale (interval scale). Scale of equal relations. Properties of measuring scales. difference property. Value property. Property of equal intervals. The existence property of a real zero. Connection of data processing methods with the scale of measurement. Relationship between the interpretation of results and the measurement scale. Psychological measurements. Measurement of the subjective reality of the subject. Subjective scaling procedures. ranking method. Method of absolute evaluation. Method of paired comparisons. Multidimensional scaling. Measurement of the characteristics of the subject and his behavior. The concept of psychodiagnostics. Statistical reliability and validity. Experimental reliability. Test reliability. Reliability of results.

5. Fundamentals of the experiment. The concept of experiment. Features of the experiment. Ideas underlying the psychological experiment. History of experimental psychology as a science. Benefits of the experiment. Ideal and real experiments. Experimental and control groups. Variables in the experiment. Zero result and its causes.

6. Experimental schemes. Experimental scheme. The internal validity of the experiment. Intergroup experimental scheme. Techniques for the distribution of subjects into groups. Random distribution (randomization). Ways to form groups randomly. Distribution by conditions. Possible reasons for the violation of the validity of the experiment when using an intergroup scheme. Intra-individual experimental scheme. Techniques for selecting the sequence of tests in the experiment. Random distribution of trials (randomization). Random distribution by blocks (block randomization). Leveling. Full equalization. Partial equalization. Latin square. Balanced latin square. Advantages and disadvantages of full and partial equalization. Possible reasons for the violation of the validity of the experiment when using an intra-individual scheme. Control group. control conditions. Choice of experimental scheme.

7. Multifactorial experimental schemes. Experiments with several independent variables. Experiments with multiple dependent variables. Advantages of complex (multifactorial) experimental schemes. Factorial experimental scheme. Complex intra-individual scheme. Mixed scheme. main effect. Interaction. Types of interaction. Interpretation of the results of complex experiments. Graphical presentation of results. Benefits of graphical presentation of results. Graphical representation of the interaction. Features and selection of complex experimental schemes.

8. Special types of experiments. The concept of experiments with a small number of subjects. Areas of application for experiments with a small number of subjects. Psychophysics. Experiments in the field of perception, memory, speech. Simulator experiments.

9. Quasi-experiments Quasi-experiments. Types of quasi-experiments. Analysis of natural events. Growing up and history as effects influencing the internal validity of quasi-experiments. Ways to increase validity - control group. Study of special cases. Longitudinal research. Schemes of longitudinal studies. Features of working with variables characterizing the subjects. Age as a special variable in psychological research. Techniques of working with age in psychological experiments. Internal validity of quasi-experimentation. Disadvantages of quasi-experiments. Possible reasons for the violation of the internal validity of quasi-experiments.

10. Problems of experimental research. Subject errors. The influence of social roles on the conduct of experiments. Errors in various types of research (descriptive and dependent observations, experiment). Errors related to the reaction of the subjects. Ways to eliminate possible errors associated with the reaction of the subjects. experimenter's error. Experimenter's preconceptions. Conscious bias. Unconscious bias. Ways to eliminate possible errors of the experimenter. Reliability of information exchange in the scientific environment. External validity of studies.

11. Data interpretation. The role of data interpretation in psychological research. Interpretation of specific results. Ceiling effect problem. The problem of return to the mean. Interpretation of stable regularities. Experimental reliability. Reliability and repetition of the experiment. Direct repetition of the experiment. Systematic repetition of the experiment. Conceptual repetition of the experiment.

12. Ethics of psychological research. The role of ethics in psychological research. Ethical problems in studies where the subjects are people. Briefing. Confidentiality and anonymity. Freedom of nonparticipation. Protection from harm. Elimination of the harmful effects of experimental research. Ethical issues in animal research. Ethical problems in the processing and analysis of experimental data. Ethical issues in reporting on a pilot study. Plagiarism in scientific papers.

13. Report on experimental psychological research. The structure of the experimental report. Standards. Experimental Report Writing Technique. What to include in a pilot report.

MAIN LITERATURE

1. Solso R., Johnson H., Beal K. Experimental psychology. Practical course. St. Petersburg: 2002

2. Gottsdanker, Robert. Fundamentals of psychological experiment. - Moscow: Moscow University Publishing House, 1982.

3. Druzhinin, V.N. Experimental psychology. - Moscow, 1997.

4. Kornilova, T.V. Experimental psychology: Theory and methods. - Moscow, 2002.

COURSE EVALUATION carried out according to the following criteria

offset

Independent work - critical review of a journal article about an experimental study

Examination - problem solving (conducted in the winter session, the assessment affects the examination grade)

Exam(2 theoretical questions)

Introduction to experimental psychology.

Introduction

The development of modern psychological science is characterized by the fact that the knowledge accumulated over decades is increasingly being applied in practice, and this practice is gradually expanding, covering more and more new areas of human activity. In contrast to past centuries, it is not the interests of academic science but life itself that dictates new research problems to psychology. If earlier psychology mainly represented abstract knowledge obtained in scientific laboratories and expounded from university departments, then applied branches of psychology are currently developing rapidly, where experiment is also widely used. However, such an experiment is focused not on obtaining the so-called "pure" knowledge, but on solving vital, practical problems and tasks.

This state of affairs corresponds to the existing division of the developed branches of psychology into strictly scientific and applied ones. Scientific directions focused on obtaining theoretical knowledge necessary for a general, fundamental solution to problems related to the knowledge of a person, his psychology and behavior. In applied industries, on a scientific basis, practical tasks are set and solved related to improving human activity, improving his behavior and raising the level of psychological development, and practical recommendations are being developed. According to this logic, scientific-cognitive and applied areas of research in educational psychology are distinguished, including experimental-scientific educational psychology and experimental-practical educational psychology, along with theoretical scientific and theoretical applied psychology. In scientific and cognitive psychological and pedagogical research, knowledge is mainly obtained that enriches the relevant science, but does not always find practical application, and in applied psychological and pedagogical research, hypotheses and assumptions are put forward and scientifically tested, the practical implementation of which should give a significant educational and educational effect. . It is primarily about the practice of teaching and educating children.

experimental psychology

It is impossible to do without an experiment in science and practice, despite its complexity and laboriousness, since only in a carefully thought out, properly organized and conducted experiment can one obtain the most conclusive results, especially those relating to cause-and-effect relationships.

experimental psychology- a field of psychology that organizes knowledge about research problems common to most psychological areas and how to solve them. Experimental psychology is called a scientific discipline about the methods of psychological research.

The application of the experiment played a major role in the transformation of psychological knowledge, in the transformation of psychology from a branch of philosophy into an independent science. The experiment in psychology became a decisive factor in the transformation of psychological knowledge; it singled out psychology from philosophy and turned it into an independent science. Various types of research of the psyche with the help of experimental methods, this is experimental psychology.

Since the end of the 19th century, scientists have come to grips with the study of elementary mental functions - human sensory systems. At first, these were the first timid steps that laid the foundation for the building of experimental psychology, separating it from philosophy and physiology.

Especially follows, noticeable Wilhelm Wundt(1832-1920), German psychologist, physiologist, philosopher and linguist. He created the world's first psychological laboratory (international center). From this laboratory, which later received the status of an institute, came a whole generation of specialists in experimental psychology, who later became the initiators of the creation of experimental psychological institutions. In his first works, Wundt put forward a plan for the development of physiological psychology as a special science that uses the method of laboratory experiment to divide consciousness into elements and clarify the regular connection between them.

Wundt considered the subject of psychology direct experience - phenomena or facts of consciousness accessible to self-observation; however, he considered the higher mental processes (speech, thinking, will) inaccessible to experiment, and proposed to study them by the cultural-historical method.

If initially the main object of experimental psychology considered internal mental processes of a normal adult, analyzed with the help of specially organized self-observation (introspection), then in the future experiments are carried out on animals (C. Lloyd-Morgan, E.L. Thorndike), mentally ill people, children are studied.

Experimental psychology begins to cover not only the study of the general patterns of the course of mental processes, but also individual variations in sensitivity, reaction time, memory, associations, etc. (F. Galton, D. Cattell).

Galton developed methods for diagnosing abilities, which laid the foundation for testing, methods for statistical processing of research results (in particular, the method for calculating correlations between variables), and mass questioning.

Kettel considered personality as a set of a certain number of empirically (with the help of tests) established and more or less autonomous psychological characteristics. Thus, in the depths of experimental psychology a new direction is emerging - differential psychology, the subject of which is individual differences between people and their groups.

Achievements in experimental psychology which at first had an "academic" character, i.e. which did not aim to apply their results to solving problems put forward by the practice of teaching, treating patients, etc., in the future they receive wide practical application in various fields of human activity - from preschool pedagogy to astronautics.

A prerequisite for the emergence of differential psychology, which studies individual differences between people and groups, at the turn of the 19th and 20th centuries was the introduction of experiment into psychology, as well as genetic and mathematical methods. Development of theoretical schemes and specific methods of experimental psychology is closely connected with the general progress of theoretical knowledge, which is most intensively taking place at the intersection of sciences - biological, technical and social.

At present, the methods of experimental psychology are widely used in various fields of human activity. The progress of human knowledge is already unthinkable without the methods of experimental psychology, testing, mathematical and statistical processing of research results. The successes of experimental psychology are based on the use of methods of various sciences: physiology, biology, psychology, mathematics

Now experimental psychology in practice, it is considered as a discipline responsible for setting up correct experiments in many areas of applied psychology, for example, to determine the appropriateness, effectiveness of a change, innovation (for example, in labor psychology). Great successes in the use of its methods have been achieved in the study of psychophysiology and the psychology of sensations and perception. However, the achievements of experimental psychology in promoting fundamental psychology are currently less significant and are in question.

Methodology of experimental psychology is based on the principles:

1. General scientific methodological principles:

2. The principle of determinism. Experimental psychology proceeds from the fact that human behavior and mental phenomena are the result of any causes, that is, they are fundamentally explicable.

3. The principle of objectivity. Experimental psychology considers that the object of cognition is independent of the cognizing subject; the object is fundamentally cognizable through action.

4. The principle of falsifiability - the requirement proposed by K. Popper to have a methodological possibility of refuting a theory that claims to be scientific by staging one or another fundamentally possible real experiment.

Specific to experimental psychology principles:

The principle of unity of the physiological and mental. The nervous system ensures the emergence and flow of mental processes, but the reduction of mental phenomena to physiological processes is impossible.

The principle of unity of consciousness and activity. Consciousness is active, and activity is conscious. An experimental psychologist studies the behavior that is formed in the close interaction of the individual with the situation. Expressed by the following function: R=f(P,S), where R is behavior, P is personality, and S is situation.

development principle. Also known as the historicism principle and the genetic principle. According to this principle, the subject's psyche is the result of a long development in phylogenesis and ontogenesis.

System-structural principle. Any mental phenomena should be considered as integral processes (The impact is always made on the psyche as a whole, and not on some isolated part of it.)

In the next chapter, we will consider the experimental method in educational psychology.

1. THE CONCEPT OF EXPERIMENTAL PSYCHOLOGY 1. IN THE EXTENSIVE MEANING: THE SCIENTIFIC DISCIPLINE STUDYING THE PROBLEM OF THE METHODS OF PSYCHOLOGICAL RESEARCH IN GENERAL. 2. ALL SCIENTIFIC PSYCHOLOGY AS A SYSTEM OF KNOWLEDGE OBTAINED ON THE BASIS OF EXPERIMENTAL STUDY OF THE PSYCHE OF HUMAN AND ANIMALS (ACCORDING TO W. WUNDTU). 3. SYSTEM OF EXPERIMENTAL METHODS AND TECHNIQUES IMPLEMENTED IN SPECIFIC INVESTIGATIONS (M. V. METLIN). 4. THE THEORY OF THE PSYCHOLOGICAL EXPERIMENT (F. J. McGUIGAN).

EXPERIMENTAL PSYCHOLOGY IS A BRANCH OF PSYCHOLOGY STUDYING THE LAWS AND REGULARITIES OF APPLICATION OF EXPERIMENT AND OTHER OBJECTIVE METHODS IN THE STUDY OF MENTAL PHENOMENA. THE OBJECT OF EXPERIMENTAL PSYCHOLOGY IS THE EXPERIMENT AND OTHER OBJECTIVE METHODS. THE SUBJECT OF EXPERIMENTAL PSYCHOLOGY IS LAWS AND REGULARITIES IN THE APPLICATION OF EXPERIMENT AND OTHER OBJECTIVE METHODS IN THE STUDY OF MENTAL PHENOMENA.

GUSTAV THEODOR FECHNER () (, GROS - ZERHEN, NEAR MUSKAU, -, LEIPZIG), GERMAN PHYSICIST, PSYCHOLOGIST, PHILOSOPHER - IDEALIST, WRITER - SATIRIST (SPOKED UNDER THE NAME OF DOCTOR MIses). HIS VIEWS INFLUENCED MANY SCIENTISTS AND PHILOSOPHERS OF THE 20TH CENTURY, INCLUDING: GERARDUS HEYMANS, ERNST MAH, WILHELM WONDT, SIGMUND FREUD, AND STANLEY HALL. FECHNER IS CONSIDERED THE CREATOR OF THE S=KLOGI FORMULA WHICH PROVES THE SCIENCE-BASED RELATIONSHIP BETWEEN BODY AND PSYCHE

WILHELM WUNDT () GERMAN PHYSIOLOGIST AND PSYCHOLOGIST. FOUNDER OF EXPERIMENTAL PSYCHOLOGY AND COGNITIVE PSYCHOLOGY. LESS KNOWN AS THE MAIN FIGURE IN SOCIAL PSYCHOLOGY, HOWEVER, THE LAST YEARS OF WUNDT'S LIFE PASSED UNDER THE SIGN (POPULATION PSYCHOLOGY), WHICH HE UNDERSTAND AS THE DOCTRINE OF THE SOCIAL BASIS OF THE HIGHER MENTAL ACTIVITY

EDWARD TITCHENER (1867–1927) STATED THAT A PSYCHOLOGICAL EXPERIMENT IS NOT A TEST OF ANY STRENGTH OR ABILITY, BUT A CUTTING OF CONSCIOUSNESS, AN ANALYSIS OF A PART OF THE PSYCHOLOGICAL MECHANISM, AND A PSYCHOLOGICAL EXPERIENCE CONSISTS IN SELF-OBSERVATION OF STANDARDS. EVERY EXPERIENCE, IN HIS OPINION, IS A LESSON OF SELF-OBSERVATION. DEVELOPED A POWERFUL TREND IN PSYCHOLOGY CALLED "STRUCTURALISM" OR "STRUCTURAL PSYCHOLOGY".

HERMANN EBBINGAUZ () GERMAN PSYCHOLOGIST. WAS AN OPPOSEON OF V. DILTEY. CARRIED OUT EXPERIMENTAL STUDIES OF MEMORY ON THE BASIS OF SYLLABLE MEMORY (1885). DEVELOPED SEVERAL METHODS FOR STUDYING MEMORY PROCESSES. DISCOVERED A NUMBER OF MEMORY PSYCHOLOGY PHENOMENA, IN PARTICULAR, "EDGE FACTOR", THAT IS A MORE EFFECTIVE MEMORIZATION OF THE FIRST AND LAST SERIES syllables. BUILT CURVES OF LEARNING AND FORGETTING - WHICH SHOW THAT THESE PROCESSES ARE NON-LINEAR. I HAVE ALSO FOUND THAT MATERIAL THAT IS MEMBERABLE IS BETTER THAN THAT IS NOT MEANINGLESS.

JAMES MCKEAN CATTEL (1860-1944) BORN MAY 25, 1860 IN USA. IN 1880 GRADUATED LAFAYETTE COLLEGE, IN 1886 RECEIVED THE DEGREE OF DOCTOR OF PHILOSOPHY FROM THE UNIVERSITY OF LEIPZIG. STUDY ALSO IN THE UNIVERSITIES OF PARIS AND GENEVA. WORKED AS ASSISTANT TO WILHELM WUNDT IN LEIPZIG. LECTURED AT THE UNIVERSITY OF CAMBRIDGE, AT THE UNIVERSITY OF PENNSYLVANIA, WHERE HE LEAD THE DEPARTMENT OF PSYCHOLOGY. IN 1891 CATTELL ACCEPTED AN INVITATION FROM COLOMBIA UNIVERSITY AND TAKEN THE POSITION OF PROFESSOR OF EXPERIMENTAL PSYCHOLOGY, BECAME DEAN OF THE DEPARTMENT OF ANTHROPOLOGY, PROFESSOR OF PHILOSOPHY AND PROFESSOR OF PSYCHOLOGY. CATTELL HAS BEEN INVESTIGATED IN HUMAN BEHAVIOR, EDUCATION, ORGANIZATION OF SCIENCE; DEVELOPED METHODS OF PSYCHOLOGICAL MEASUREMENTS.

ALFRED BINET () FRENCH PSYCHOLOGIST, DOCTOR OF MEDICINE AND LAW OF THE UNIVERSITY OF PARIS, FOUNDER OF THE FIRST FRANCE LABORATORY OF EXPERIMENTAL PSYCHOLOGY. STRIVED TO APPROVE THE OBJECTIVE METHOD OF RESEARCH IN PSYCHOLOGY. KNOWN, FIRST OF ALL, AS THE COMPILER (TOGETHER WITH T. SIMON IN 1905) OF THE FIRST PRACTICAL INTELLIGENCE TEST, CALLED "SIMON BINET'S MENTAL DEVELOPMENT SCALE" (ANALOGUE OF THE MODERN IQ-TEST). LATER IN 1916, THE SIMON BINET SCALE WAS REWORKED BY L. THERMEN INTO THE STANFORD BINET INTELLIGENCE SCALE

HEINRICH RORSCHACH (1884-1922) SWEDISH PSYCHIATRIST. INVENTED THE TEST NAMED AFTER HIM, WHICH BECAME ONE OF THE MAIN MEANS OF PSYCHODIAGNOSTIC STUDY OF THE PERSONALITY, ITS STRUCTURE AND UNCONSCIOUS MOTIVATION. THE TEST CONSISTS IN INTERPRETATION BY THE SUBJECT OF A SET OF INK SPOTS OF DIFFERENT CONFIGURATION AND COLOR, THAT HAVE A DEFINITE SENSE FOR DIAGNOSTICS OF HIDDEN INSTALLATIONS, IMPLEMENTATIONS, CHARACTER PROPERTIES. R.'S WORK GIVES AN IMPULSE TO THE DEVELOPMENT OF ONE OF THE MAIN DIRECTIONS IN MODERN PSYCHODIAGNOSTICS, BECAUSE IT ALLOWED TO APPROACH TO CONSIDERATION OF THE PERSONALITY AS A WHOLE, NOT A TOTALITY OF SEPARATE ABILITIES

DIFFERENTIAL PSYCHOLOGY, A BRANCH OF PSYCHOLOGY STUDYING INDIVIDUAL DIFFERENCES BETWEEN PEOPLE. A PREREQUISITE FOR THE APPEARANCE OF "DIFFERENTIAL PSYCHOLOGY" AT THE TURN OF THE 19TH AND 20TH CENTURIES WAS THE INTRODUCTION OF EXPERIMENT INTO PSYCHOLOGY, AS WELL AS GENETIC AND MATHEMATICAL METHODS. THE PIONEER IN THE DEVELOPMENT OF DIFFERENTIAL PSYCHOLOGY WAS F. GALTON (GREAT BRITAIN), WHO INVENTED A NUMBER OF TECHNIQUES AND INSTRUMENTS FOR THE STUDY OF INDIVIDUAL DIFFERENCES. W. STERN (GERMANY) INTRODUCED THE TERM "DIFFERENTIAL PSYCHOLOGY" (1900). THE FIRST MAJOR REPRESENTATIVES OF DIFFERENTIAL PSYCHOLOGY WERE A. BINET (FRANCE), J. CATTEL (USA) AND OTHERS

FRANCIS GALTON () ENGLISH EXPLORER, GEOGRAPHER, ANTHROPOLOGIST AND PSYCHOLOGIST; FOUNDER OF DIFFERENTIAL PSYCHOLOGY AND PSYCHOMETRIC. GALTON. INTRODUCED THE CONCEPT OF HEREDITY IN PSYCHOLOGY AND ANTHROPOLOGY GALTON INTRODUCED THE CONCEPT OF HEREDITY IN PSYCHOLOGY AND ANTHROPOLOGY

WILLIAM LEWIS STERN () GERMAN PSYCHOLOGIST AND PHILOSOPHER, CONSIDERED ONE OF THE PIONEERS OF DIFFERENTIAL AND PERSONAL PSYCHOLOGY. In addition, ROMO HAVE A GREAT INFLUENCE ON THE NARROWING CHILD PSYCHOLOGY. THE CREATOR OF THE CONCEPT OF INTELLIGENT COEFFICIENT, WHICH LATER WAS BASED ON ALFRED BINET'S FAMOUS IQ TEST. FATHER OF THE GERMAN WRITER AND PHILOSOPHER GUNTER ANDERS. IN 1897, STERN INVENTED A TONE VARIATOR, WHICH ALLOWED HIM TO SIGNIFICANTLY EXPAND THE POSSIBILITIES OF STUDYING HUMAN SOUND PERCEPTION.

SIGMUND FREUD () AUSTRIAN PSYCHOLOGIST, PSYCHIATRIST AND NEUROLOGIST, FOUNDER OF THE PSYCHOANALYTICAL SCHOOL OF THE THERAPEUTIC DIRECTION IN PSYCHOLOGY, POSTULATES THE THEORY ACCORDING TO WHICH HUMAN NEUROTIC DISORDERS ARE CAUSED BY

CARL GUSTAV JUNG () Swiss psychiatrist, founder of one of the areas of depth psychology, analytical psychology. In 1912, Jung published The Psychology of the Unconscious, which refuted many of Freud's ideas; two years later he resigned as president of the International Psychoanalytic Society. In 1921, the work "Psychological Types" was published, in which Jung divided all people into introverts and extroverts, and also substantiated his theory of archetypes for the first time.

IVAN MIKHAILOVICH SECHENOV () RUS. NATURAL SCIENTIST, RESEARCHER OF PSYCHOLOGY AND THE THEORY OF KNOWLEDGE, FOUNDER OF PHYSIOLOGICAL SCHOOL AND NATURAL SCIENTIFIC DIRECTION IN PSYCHOLOGY IN RUSSIA. IN THE WORK "REFLEXES OF THE BRAIN" (1863) DEVELOPED THE DOCTRINE OF THE BRAIN MECHANISMS OF CONSCIOUSNESS AND WILL; PUSHED OUT, BASED ON THE DISCOVERY OF "CENTRAL INHIBITION" - BRAKING INFLUENCE OF THE NERVE CENTERS ON BEHAVIOR, - THE PROPOSITION THAT ALL ACTS OF CONSCIOUS AND UNCONSCIOUS MENTAL LIFE ACCORDING TO THE METHOD OF ORIGIN ARE REFLEXES; APPROVED THE PRINCIPLE OF SELF-REGULATION AND SYSTEM ORGANIZATION OF NERVOUS-MENTAL ACTIVITY. FOR THE FIRST TIME HAS DESIGNATED THE CONCEPT OF FEEDBACK AS A NECESSARY REGULATOR OF BEHAVIOR. SECHENOV'S DOCTRINE PROMOTED THE DEVELOPMENT OF PHYSIOLOGY AND PSYCHOLOGY IN RUSSIA; ACCEPTED BY IP PAVLOV, VM BEKHTEREV, LS VYGOTSKY AND THEIR STUDENTS, IT BECAME THE BASIS FOR THE SYSTEMIC STUDY OF THE LIFE OF THE ORGANISM AND ITS FUNCTIONS.

IVAN PETROVICH PAVLOV () ACADEMICIAN, PROFESSOR OF PHYSIOLOGY, FAMOUS RUSSIAN SCIENTIST, CREATOR OF THE STUDY ABOUT "CONDITIONAL REFLEXES". His main work - "Twenty years of experience of an objective study of the highest nervous activity (behavior) of animals" (Collection of articles, speeches, reports) - was published in 1923. I. P. Pavlov and his students first gave accurate experimental confirmation by theoretical views of Sechenov, FATHER OF RUSSIAN PHYSIOLOGY. IN 1863 SECHENOV PUBLICATED THE BOOK "BRAIN REFLEXES" IN WHICH, FAR AWAY OF THE VIEWS OF HIS TIME, CONSIDERED PSYCHOLOGY AS A PART OF PHYSIOLOGY, REDUCING THE SCIENCE OF MENTAL PROCESSES TO THE STUDY OF MOTOR (MUSCLE) ACTIVITY. Based on the idea of ​​Sechenov about the reflex mechanism, as a common basis of mental life, Pavlov has taken an analysis of the activities of body workers (muscles and glands), considering it as a set of reactions to external irritation committed by the body in order to fit the environment.

BEKHTEREV VLADIMIR MIKHAILOVICH () RUSSIAN PHYSIOLOGIST, NEUROPATHOLOGIST, PSYCHIATRIST, PSYCHOLOGIST. FOUNDED THE FIRST IN RUSSIA EXPERIMENTAL - PSYCHOLOGICAL LABORATORY (1885), AND THEN THE PSYCHONEUROLOGICAL INSTITUTE (1908) - THE FIRST IN THE WORLD CENTER FOR COMPREHENSIVE STUDY OF HUMANS. BASED ON THE REFLECTOR CONCEPT OF MENTAL ACTIVITY PROPOSED BY IM SECHENOV, HE DEVELOPED A NATURAL SCIENTIFIC THEORY OF BEHAVIOR. ARISING IN OPPOSITION TO THE TRADITIONAL INTROSPECTIVE PSYCHOLOGY OF CONSCIOUSNESS, THEORY B. ORIGINALLY RECEIVED THE NAME OF OBJECTIVE PSYCHOLOGY (1904), THEN PSYCHOREFLEXOLOGY (1910) AND, FINALLY, REFLEXOLOGY (1917). B. MADE A MAJOR CONTRIBUTION TO THE DEVELOPMENT OF DOMESTIC EXPERIMENTAL PSYCHOLOGY ("GENERAL FOUNDATIONS OF HUMAN REFLEXOLOGY", 1917).

Alexander Fedorovich Lazur () The founder of the domestic differential psychology, author of fundamental work on the nature and classification of personalities, the creator and head of the psychological laboratory under the psychoneurological institute, the author and developer of the method of natural experiment in psychology. LAZURSKY PROPOSED THE CONCEPT OF A MULTILEVEL ORGANIZATION OF THE HUMAN PSYCHE ("AN ESSAY OF THE SCIENCE OF CHARACTERS", 1909).

GRIGORY IVANOVICH ROSSOLIMO () IN 1908, G. I. ROSSOLIMO PUBLISHES A SCALE FOR MEASURING THE LEVEL OF DEVELOPMENT OF GENERAL ABILITIES, INCLUDED IN THE HISTORY OF PSYCHOLOGY AND PSYCHODIAGNOSTICS UNDER THE NAME "PSYCHOLOGICAL PROFILES". CONSTRUCTING THE TEST, HE WAS NOT BY THE EMPIRICAL WAY, BUT DEVELOPED A SYSTEM OF THEORETICAL CONCEPTS ABOUT THE STRUCTURE OF PERSONALITY AND INTELLIGENCE. THE AUTHOR CONSIDERED THE MAIN PURPOSE OF HIS TEST TO DEVELOP CRITERIA FOR THE DIFFERENCE OF NORMAL CHILDREN FROM THAT HAVE DIFFERENT DEGREES OF MENTAL retardation.

DURING THE SOVIET PERIOD IN PEDOLOGY AND PSYCHOTECHNOLOGY THE PRACTICE OF TESTING IS GAINING SPEED. TESTS GET THE BROADEST APPLICATION, FIRST OF ALL IN EDUCATIONAL INSTITUTIONS. M. Ya. D. LEVITOV, A. A. LYUBLINSKAYA, G. I. ROSSOLIMO, I. N. SPIELREIN, A. M. SHUBERT AND OTHERS

LEV SEMENOVICH VYGOTSKY () L. S. VYGOTSKY IS THE OUTSTANDING DOMESTIC PSYCHOLOGIST, LEAVED A BRIGHT MARK IN SCIENCE AND PRACTICE, LAYED THE FOUNDATIONS OF THE DOMESTIC WHICH SUBJECT INFLUENCES OTHERS, FORMES OWN INTERNAL WORLD, PSYCHODIAGNOSTICS. HE DEVELOPED A DOCTRINE ON THE DEVELOPMENT OF MENTAL FUNCTIONS IN THE PROCESS OF INDIVIDUAL MASTERING OF CULTURAL VALUES MEDIATED BY COMMUNICATION. CULTURAL KNOWLEDGE, FIRST OF ALL THE SIGNS OF A LANGUAGE, SERVE A KIND OF TOOLS, OPERATING THE BASIC UNITS OF WHICH ARE MEANINGS AND MEANINGS

ALEXANDER ROMANOVICH LURIIA () FOLLOWING THE IDEAS OF L. S. VYGOTSKY, LURIIA DEVELOPED A CULTURAL AND HISTORICAL CONCEPT OF THE DEVELOPMENT OF THE PSYCHE, PARTICIPATED IN CREATING THE THEORY OF ACTIVITY. ON THIS BASIS I DEVELOPED THE IDEA OF A SYSTEMIC STRUCTURE OF THE HIGHER MENTAL FUNCTIONS, THEIR VARIABILITY, PLASTICITY, EMPHASIZING THE LIFETIME NATURE OF THEIR FORMATION, THEIR IMPLEMENTATION IN VARIOUS TYPES OF ACTIVITY. STUDYED RELATIONS OF HEREDITY AND EDUCATION IN MENTAL DEVELOPMENT.

2. SCIENTIFIC RESEARCH SCIENCE IS A SPHERE OF HUMAN ACTIVITY, THE RESULT OF WHICH IS NEW KNOWLEDGE OF REALITY, MEETING THE CRITERION OF TRUTH AND CHARACTERIZED BY A METHOD. CRITERIA OF TRUE (SCIENTIFIC) KNOWLEDGE: - ANY THEORY IS A TEMPORARY CONSTRUCTION AND CAN BE DESTROYED. - KNOWLEDGE THAT CAN BE REFUTED IN THE PROCESS OF EMPIRICAL VERIFICATION IS RECOGNIZED AS SCIENTIFIC KNOWLEDGE. - KNOWLEDGE FOR WHICH THERE IS NO APPROPRIATE PROCEDURE FOR REFUTATION CANNOT BE SCIENTIFIC.

THEORY IS A SUMMARY AND CAN BE REFUTED BY EXPERIMENT EXPERIMENT IS A METHOD OF REFUTING plausible HYPOTHESES. METHODOLOGICAL PRINCIPLES: 1. FALSIFIABILITY PRINCIPLE - - POTENTIAL REFUTABILITY OF THE THEORY; - ABSOLUTE REFUTATION OF THE THEORY IS ALWAYS FINAL. 2. THE PRINCIPLE OF VERIFIABILITY - ANY HYPOTHESIS CAN BE REFUTED AFTER (RELATIVELY)

THE EXPERIMENTAL METHOD IN PSYCHOLOGY THE EXPERIMENTAL METHOD IS A FIXED SYSTEM OF MEANS, TECHNIQUES AND PROCEDURES THAT ALLOW TO GET RELIABLE AND RELIABLE KNOWLEDGE ABOUT MENTAL PHENOMENA. IT IS BASED ON THE FACT THAT A HUMAN REALIZES HIS INNER POTENTIAL IN THE FORM OF ACTIVITY (BEHAVIOR, ACTIVITY, COMMUNICATION, GAMES, ETC.), WHICH IS CARRIED OUT IN A PARTICULAR SITUATION. ANALYZING ACTIVITY, CORRELING IT, ON THE ONE HAND, WITH A HUMAN AS A SUBJECT, ON THE OTHER – WITH A SITUATION, THE RESEARCHER GETS THE POSSIBILITY TO RECONSTRUCT THE STRUCTURES AND PROCESSES OF THE INTERNAL WORLD, WITHOUT WHICH THE OBSERVED ACTIVITY WOULD BE IMPOSSIBLE.

STATES (PHASES) OF SCIENCE (ACCORDING TO T. KUHN): 1. REVOLUTIONARY PHASE (BREAKING THE PARADIGMA). 2. "NORMAL SCIENCE" - THE RULES AND STANDARDS OF SCIENTIFIC ACTIVITY, ADOPTED BY THE SCIENTIFIC COMMUNITY, BEFORE THE NEXT REVOLUTION BREAKING THE OLD PARADIGM. STAGES OF THE NORMATIVE PROCESS OF SCIENTIFIC RESEARCH: HYPOTHESIS (HYPOTHESIS). RESEARCH PLANNING. CONDUCTING RESEARCH. DATA INTERPRETATION. REFUTATION OR NON-REFUTATION OF HYPOTHESES. (FORMING A NEW HYPOTHESIS).

TYPES OF SCIENTIFIC RESEARCH 1. FUNDAMENTAL (WITHOUT CONSIDERATION OF THE PRACTICAL EFFECT). 2. APPLIED (FOR SOLVING A SPECIFIC PROBLEM). 3. MONODISCIPLINARY AND COMPLEX. 4. SINGLE-FACTORY (ANALYTICAL) - IDENTIFICATION OF THE MOST SIGNIFICANT ASPECT. 5. SEARCH (ISSUES PREVIOUSLY UNSOLVED). 6. CRITICAL (REFUTATION OF THE EXISTING THEORY, CHOICE FROM ALTERNATIVE HYPOTHESES). 7. REPRODUCER.

TYPES OF SCIENTIFIC THEORIES 1. AXIOMATIC (BASED ON AXIOMS ​​UNPROVED IN THE FRAMEWORK OF THE THEORY) AND HYPOTHETIC-DEDUCTIVE (BASED ON ASSUMPTIONS - HYPOTHESIS). 2. QUALITATIVE THEORIES (WITHOUT INVOLVING MATHEMATICAL EQUIPMENT). 3. FORMALIZED THEORIES (USING THE MATHEMATICAL APPARATUS).

A HYPOTHESIS IS A SCIENTIFIC ASSUMPTION THAT HAS NOT BEEN CONFIRMED OR REFUTED YET. - MAY BE REJECTED, BUT NEVER FINALLY ACCEPTED; - OPEN FOR FURTHER CHECK. I. TYPES OF HYPOTHESES (BY ORIGIN): 1. THEORETICAL (THE THEORETICALLY JUSTIFIED; TO CHECK THE CONSEQUENCES OF THE THEORY). 2. EXPERIMENTAL (FOR CONFIRMATION / REFUTATION OF THE THEORIES). 3. EMPIRICAL (regardless of theory; FOR THIS PARTICULAR CASE).

II. TYPES OF HYPOTHESES (BY CONTENT) 1. ABOUT THE PRESENCE OF THE PHENOMENON (DOES IT EXIST?). 2. ON THE PRESENCE OF RELATIONS BETWEEN PHENOMENA (CORRELATION STUDY). 3. ON THE PRESENCE OF A CAUSAL RELATION BETWEEN THE PHENOMENA - EXPERIMENTAL HYPOTHESES: - BASIC (1-2) AND ALTERNATIVE. - HYPOTHESIS ABOUT THE DIFFERENCE (H 1). - HYPOTHESIS OF SIMILARITY (Н 0).

THE CONCEPT OF AN IDEAL RESEARCH THE RESULTS ARE OBJECTIVE, INVARIANT WITH RESPECT TO TIME, SPACE AND THE TYPE OF OBJECTS OF STUDY. IDEAL RESEARCH IS INTERSUBJECTIVE. IDEAL RESEARCH CANNOT AND SHOULD NOT COMPLETELY CORRECT WITH REAL RESEARCH. THE SCIENTIFIC METHOD SHOULD GIVE A RESULT AS APPROXIMATE TO THE IDEAL. CONCEPT AND TYPES OF VALIDITY.

experimental psychology

Lecture course

Introduction to experimental psychology

Methods and results of multidimensional studies of individual - psychological characteristics of personality

Data collection methods

Multivariate data analysis methods

Psychological testing

General issues of test reliability.

Approaches to the study of the validity of tests.

Methodology for solving psychodiagnostic problems

Statistics and test processing

Main Experiment

Correlation analysis

Conclusion

Literature

Introduction to experimental psychology

In practical life, personality theories do not play a significant role. The human psyche is an extremely complex phenomenon and presents significant difficulties for study.

The systematization of psychological knowledge about a person can be conditionally divided into clinical-psychological and experimental. The first arose from verbal theories and observations as a desire to treat and correct deviant behaviors. Many prominent psychologists are known in this field of psychology (Adler, Bekhterev, Freud, and many others). While scientific in purpose, these theories have achieved popularity without a rigorous experimental basis. Measurement here is replaced by observation, data collection - by the selection of representative cases, statistical processing - by meaningful interpretation. However, this poverty of the experimental procedure makes it possible to manipulate a large number of explanatory variables. It is important that the supporters of the clinical method try to bring into a single system all the variables necessary for the formation of concepts about personality, without which it is impossible to come to the establishment of real patterns.

Experimental psychology arose as a reaction to the verbal nature of the clinical psychological research method. Quantitative experimental research is divided into two-dimensional and multidimensional. Both approaches allow you to explore relationships between variables, but in different ways.

The two-dimensional experiment is a transfer of the research method adopted in the physical sciences. It involves the selection of dependent and independent variables using experimental control. In a multidimensional experiment, all the measured factors, taken in their entirety, are statistically taken into account at the same time.

Proponents of the two-dimensional experimental method believe that the selection of two variables is necessary to study the mental phenomenon in its purest form. In their opinion, with this approach, secondary factors are eliminated. But the mental process never proceeds in isolation. Behavior is complex and determined by many internal and external factors. For this reason, they try to form two groups of persons identical in all respects except one, and it is impossible to put them in the same conditions even in a laboratory experiment.

A multivariate experiment requires the measurement of a set of accompanying features, the independence of which is not known in advance. An analysis of the relationships between the studied traits makes it possible to reveal a small number of hidden structural factors on which the observed variations in the measured variables depend. This approach is based on the assumption that the initial features are only superficial indicators, indirectly reflecting personality traits hidden from direct observation, the knowledge of which will make it possible to simply and clearly describe individual behavior. Thus, a multidimensional approach is applied in areas where human behavior is considered in natural settings. What cannot be achieved by direct manipulation of the dependent and independent variables can be achieved by more sophisticated statistical analysis of the entire set of significant variables. The main advantage of the multidimensional approach is its efficiency in the study of real situations without the risk of their distortion by side effects arising from the creation of artificial experimental conditions.

Introduction to experimental psychology.

How to start psychological research.

Literature - - Ch. 2:54-65, ch. 10, - Ch. 1.6, - ch.4

Experiment

In any experiment, there is an object of study (behavior, phenomenon, property, etc.), in addition, in an experiment, usually

something changes

potential sources of influence are constant

any behavior is measured

Under variable in psychology, they understand any quantity, property or parameter that interests us. This can be either a quantitatively measurable value (such as height, weight, reaction time, sensation thresholds, etc.) or quantities that allow only a qualitative description (for example, gender, race, mood, character, etc.)

independent research dependent

variable variable

control variables

Independent variable is a variable changed by the experimenter; includes two or more states (conditions) or levels.

Dependent variable- a variable that changes under the action of an independent variable, taking on different values ​​that are measured.

Control variable is a variable that is kept constant.

The researcher changes the independent variable so that the effects (influence) of different values ​​or levels of the independent variable can be determined from changes in the dependent variable.

At the same time, the main difficulty for us is to ensure the constancy of the control variables. If in the course of the experiment, along with the independent variable we have identified, some other variable also changes, which can also have an effect on the dependent variable, then we say that there is mixing effect.

Mixing due to the fact that the action of the independent variable is accompanied by a number of other variables that can systematically differ when different conditions are presented to the independent variable, and thus have a favorable (or unfavorable) effect on the action of one of them.

The confusion is caused by the fact that when designing the experiment, we did not take into account any variable or did not check whether it is really included in the control variables and, thereby, made it an independent variable.

research project

includes the following steps

search for an idea	Sources of ideas · observations · experts · magazines, books, textbooks, etc.
formulation of the hypothesis to be tested	A testable hypothesis is a statement about an assumed or theoretical relationship between two or more variables. The hypothesis being tested either states explicitly or implies implicitly that the variables measurable.
analysis of relevant literature	The literature review serves not to reinvent the wheel, i.e., to determine what is already known about your hypothesis. Literature review helps to develop a reasonable research plan, select the appropriate material and incentives. .
development of the experimental scheme
conducting pretests (pilot studies)	The preliminary tests use a small number of subjects. This is done to check whether there are errors in the design and procedure of the experiment whether the subjects understand the instructions how long the experiment will take whether the tasks are too difficult or easy. At the same time, we will train ourselves in practice to observe and measure the behavior of interest to us.
data collection
statistical data analysis	Usually the logic of hypothesis testing is as follows: the experimenter selects conditions (experimental and control) to test his hypothesis, assuming that the experimental conditions will cause some effect compared to the control conditions. This hypothesis is tested against null hypothesis. A null hypothesis is a statement that there is no relationship between the selected variables. An experiment is considered successful when it succeeds in rejecting the null hypothesis, i.e. show that it is false, and, therefore, the initial hypothesis about the presence of a connection is true.
data interpretation	Getting the data is not enough - you still need to interpret it. It's just that data has no value in and of itself, it must be correlated with a theory that explains behavior.
report

Measurements in psychology

Literature - - Ch. 6 + see almost any psychology dictionary +

+ Sidorenko E.V. Methods of mathematical processing in psychology. St. Petersburg, 1996.

MEASURING SCALE

A strict definition of the scale is quite difficult.

It is easier to say that a scale is a rule by which we put names (numbers) in accordance with objects or properties of objects.

Measuring scale types

Usually there are 4 types of measuring scales (Druzhinin, 1997, Elmes et al, 1992, Stevens, 1951):

naming scale (nominal scale, nominal scale)

order scale (ordinal scale, ordinal scale)

interval scale (interval scale, interval scale)

scale of equal ratios (ratio scale)

Scale types are defined by the properties they possess. Scale types are listed below with increasing information content. Each subsequent scale has the properties of the previous scale and additional ones. This means, in particular, that the statistical procedures that can be used for the scale of names are also suitable for all others. But statistics for the scale of equal ratios will not work for the three less informative scales.

name scale	measures the property of difference in some way and nothing else. The naming scale simply sorts objects into different categories. Examples
order scale	Reflects the difference in the value of some property. The values ​​of the scale are assigned to the values ​​of some property so that the order reflects the order in which the value of this property changes in the selected objects. Such a scale shows the order in which objects are arranged according to the selected indicator, without giving any information about the real values ​​of this indicator. Sometimes such scales may have a zero that matches the "zero" of the selected property. The order scale assumes a monotonic relationship between the divisions of the scale and the parameter exponent. Examples
interval scale interval scale	has the properties of difference, magnitude and equal intervals. In this scale, not only the scale values, but also the interval values ​​make sense. In the scale of intervals, the value of the difference between the values ​​of the scale somehow reflects the difference in the possession of the selected property. The interval scale assumes a linear relationship between the scale divisions and the parameter indicator. Examples
relationship scale	has all the properties of the previous scales and, in addition, has a real zero - that is, the zero of the scale corresponds to the "zero" of some selected property. Then the value of the scale corresponds to the difference in the manifestation of some property in relation to its "zero". This is the most powerful scale. In such scales, not only the difference, but also the ratio of values ​​makes sense (for example, in n times the scale value corresponds to n times the value of the index). Examples

Scale type:

determines which statistical procedure we will use (see table)

helps to critically evaluate the research of others

influences the interpretation of data, as different scales reflect different properties.

Only from the scale of intervals does it make sense to talk about the average values ​​of some indicator. So, for example, if we refer IQ to a scale of intervals, then we can talk about the average of the group, which will allow us, say, to compare the average IQ of schoolchildren in different countries. If IQ is a scale of order, then the concept of the average loses its meaning and there can be no average IQ of the group.

Only on a scale of equal ratios can we speak of percentages. So, for example, we will be able to claim that a certain technique has allowed us to increase creativity by 20% only when creativity is measured on a scale of equal ratios.

DESCRIPTIVE OBSERVATIONS

The most obvious way to make observations is in psychology;

It aims to describe behavior.

Descriptive observations list what behavior occurs, with what frequency and in what sequence, and in what quantity.

There are 3 types of descriptive observations: naturalistic, precedents (special cases) and reviews.

Benefits of descriptive observations:

useful in the early stages of research

useful when other methods are not available

Disadvantages:

Doesn't make it possible to draw conclusions about relationships between variables

the impossibility of repetition makes them extremely subjective

Anthromorphism (attributing human characteristics to animals and even inanimate objects)

internal invalidity, since such methods allow a) to select cases from a whole bunch of cases, as well as to select questions, answers and facts; b) relate these cases and answers to our predetermined theory, and thus "prove" any theory. Example: Freud's theory. Whatever Freud's genius, his theory does not stand up to scrutiny in terms of the facts and evidence on which it is based.

DEPENDENT OBSERVATIONS

These are observations of relationships, dependencies between various phenomena and properties. To study such a dependence, we can use the correlation technique. Using the correlation technique allows us to determine the degree of relationship between two variables of interest. We usually do this with the hope that we can predict the other from one variable. Such conclusions are made "ex post facto", that is, after what happened. First, observations about the behavior of interest are collected and then a correlation coefficient is calculated, which expresses the degree of relationship between two variables or measurements.

Variables in Experiments

independent	The experimenter chooses them on the basis that they can cause changes in behavior. When changes in the level (value) of the independent variable lead to a change in behavior, we say that the behavior is controlled by the independent variable. If the independent variable does not control the behavior, then it is called a null result. A null result can have several interpretations: 1. The experimenter erred in thinking that the independent variable affects behavior. Then the null result is true. 2. Changes in the independent variable were not valid.
dependent	They depend on the behavior of the subjects, which, in turn, depends on independent variables. A good dependent variable should be reliable (i.e. when we repeat the experiment - same subjects, same levels of independent variables, ... - the dependent variable should be about the same. The dependent variable is unreliable if there are problems with the way it is measured. Another problem with the dependent variable that can result in a null result is that the dependent variable is stuck at the lowest or highest end of the scale.This is called a ceiling effect.This effect prevents the influence of the independent variable from showing up on the dependent variable.Finally, a null result may appear due to statistical processing of data.The results of a statistical test may not confirm the null hypothesis is false, while it is not true.
control	In any experiment, there are more variables than can actually be controlled, i.e. there are no perfect experiments. The experimenter tries to control as many significant variables as possible and hopes that the remaining uncontrolled variables will have a small effect compared to the effect of the independent variable. The smaller the effect of the independent variable, the tighter the control should be. Null results can also be obtained if there is insufficient control over various factors. This is especially true for non-laboratory conditions. You may remember that we call the influence of these uncontrollable factors confounding.

EXPERIMENTAL SCHEMES

Literature - - Ch. 3, 4, 6, - Ch. 2, 7, 8, - Ch. five

There are two main possibilities:

distribute several subjects to each level of the independent variable

Distribute all test subjects to all levels

The first possibility is called

intergroup experimental design- this is the presentation of each of the conditions of the independent variable to different groups of subjects.

The second possibility is called

Intra-individual experimental scheme - this is the presentation of all the conditions under study to one (or several) subjects. Sometimes such a scheme is also called the scheme of an individual experiment or intragroup .

Types of interaction

Main effects are statistically independent of interaction effects. This means that knowing the magnitude and direction of the main effects, we cannot say anything about the interaction.

Example. Consider an experiment with two independent variables, 1 and 2. Independent variable 1 has two levels, A and B. Independent variable 2 also has two levels, 1 and 2. In all three cases shown below, the main effects of these variables are the same (the difference in the dependent variable between two levels of independent variable 1 is 20 units, and the difference between two levels of independent variable 1 is 60 units).

3) And in this case there is an intersecting interaction

Independent variable 1
BUT	IN	B-A

Independent variable 2
		2-1

	BUT	IN	the average
the average

This is an intersecting interaction. It is the most reliable, as it cannot be explained by measurement and scaling problems of the dependent variable.

The main effects in the tables are the same, but the graphs are all different.

Morality: The interaction must be considered before drawing conclusions in an experiment where there is more than one independent variable.

MIXED SCHEME

This is a scheme where one or more intergroup variables and one or more intra-individual variables are used.