The philosophy of a science of behavior; there are various forms of behaviorism. (See methodological behaviorism, radical behaviorism.) 

The assumption that the universe is a lawful and orderly place in which phenomena occur in relation to other events and not in a willy-nilly, accidental fashion. 

The objective observation of the phenomena of interest; objective observations are “independent of the in- dividual prejudices, tastes, and private opinions of the sci- entist. . . . Results of empirical methods are objective in that they are open to anyone’s observation and do not de- pend on the subjective belief of the individual scientist” 

A carefully controlled comparison of some mea- sure of the phenomenon of interest (the dependent vari- able) under two or more different conditions in which only one factor at a time (the independent variable) differs from one condition to another. 

A natural science approach to the study of behavior as a subject matter in its own right founded by B. F. Skinner; methodological features include rate of response as a basic dependent vari- able, repeated or continuous measurement of clearly de- fined response classes, within-subject experimental comparisons instead of group design, visual analysis of graphed data instead of statistical inference, and an em- phasis on describing functional relations between behav- ior and controlling variables in the environment over formal theory testing. 

A fictitious or hypothetical variable that often takes the form of another name for the observed phe- nomenon it claims to explain and contributes nothing to a functional account or understanding of the phenomenon, such as “intelligence” or “cognitive awareness” as expla- nations for why an organism pushes the lever when the light is on and food is available but does not push the lever when the light is off and no food is available. 

A verbal statement summarizing the re- sults of an experiment (or group of related experiments) that describes the occurrence of the phenomena under study as a function of the operation of one or more spec- ified and controlled variables in the experiment in which a specific change in one event (the dependent variable) can be produced by manipulating another event (the inde- pendent variable), and that the change in the dependent variable was unlikely the result of other factors (con- founding variables); in behavior analysis expressed as b = f (x1), (x2), . . . , where b is the behavior and x1, x2, etc., are environmental variables of which the behavior is a function. 

A presumed but unobserved process or entity (e.g., Freud’s id, ego, and superego). 

An approach to explaining behavior that assumes that a mental, or “inner,” dimension exists that differs from a behavioral dimension and that phenomena in this di- mension either directly cause or at least mediate some forms of behavior, if not all. 

The practice of ruling out simple, logical  explanation nations, experimentally or conceptually, before consider- ing more complex or abstract explanations. 

An attitude that the truthfulness and va- lidity of all scientific theory and knowledge should be con- tinually questioned. 

A thoroughgoing form of behaviorism that attempts to understand all human behavior, including private events such as thoughts and feelings, in terms of controlling variables in the history of the person (on- togeny) and the species (phylogeny). 

(a) Repeating conditions within an experiment to determine the reliability of effects and increase internal validity. (See baseline logic, prediction, verification.) (b) Repeating whole experiments to determine the gener- ality of findings of previous experiments to other subjects, settings, and/or behaviors. (See direct replication, ex- ternal validity, systematic replication.) 

A systematic approach to the understanding of nat-

ural phenomena (as evidenced by description, prediction, and control) that relies on determinism as its fundamental assumption, empiricism as its primary rule, experimenta- tion as its basic strategy, replication as a requirement for believability, parsimony as a value, and philosophic doubt as its guiding conscience.