operant

n. a class of responses that produces a common effect on the environment. An operant is defined by its effect rather than by the particular type of behavior producing that effect. A distinction may be made between the behavior required to achieve the effect and those alternative forms of behavior that constitute the class and may also occur. In the former, the class might include all forms of behavior that result in a lever being moved 4 mm downward (see descriptive operant). In the latter case, the class includes all forms of behavior that become more probable; for example, a rat’s two-handed lever presses might increase in probability, but one-handed presses might not (see functional operant). Compare respondent.