Glossary of Psychology

Behaviorism: The school of psychology, founded by John Watson, which asserts that the relationship between observable stimuli and responses is the only appropriate subject matter of psychology.

Case study: A research procedure by which current, historical, and biographical information is collected for a single individual.

Control group: An essential part of any experiment, this group of subjects does not experience the researcher’s manipulation and thus constitutes a standard against which the treatment effects can be compared.

Correlation coefficient: A statistic or numerical value indicating the degree of relationship between two sets of data (for example, height and weight).  Correlational method: A research procedure for finding the relationship between variables; causality cannot be inferred in studies using this method.

Dependent variable: In an experiment, the behavior that is expected to vary with (or depend upon) the independent variable.

Experimental hypothesis: A testable statement of the relationship between two or more variables.

Experimental method: This is the most effective research technique because it allows causal relationships to be determined; this method includes at least one control group and random assignment.

External validity: The extent to which experimental findings can be generalized to other populations, settings, treatments, and so forth.

Functionalism: An early school of psychology that focused on the adaptive functions behavior and consciousness.

Gestalt psychology: An early school of psychology that emphasized the patterns, organization, and wholeness of human experience. Independent variable: In an experiment, the factor that is controlled by the experimenter and is expected to influence the subject’s behavior.

Internal validity: Quality attributed to experiments that have been designed and conducted so that competing explanations of their findings are implausible.

Introspection: A procedure used by early psychologists to try to describe the contents of the mind; accordingly, trained observers reported the experiences produced by various stimuli.

Psychoanalysis: A therapeutic method developed by Freud for treating mental patients. Freud’s theory of personality, which stresses the importance of unconscious motives, was based on his experiences with the psychoanalytic method.

Psychology: The scientific study of behavior and related mental and physical processes.

Random assignment: The procedure used in experiments to make sure that each subject has an equal chance of being assigned to any of the groups.

Science: Systematized knowledge that is secured by means of observation, experimentation, and theory construction.

Statistical significance: Research results that have a low probability of occurring simply because of chance.

Structuralism: An early school of psychology that emphasized introspection to reveal the basic elements of consciousness and the structure of the mind.

Treatment group: In an experiment, the group of subjects that is exposed to the researcher’s manipulation (as opposed to the control group which is not).