Functional analysis is defined as a central feature of behavioral assessment. In a Functional analysis, careful analyses are made of the stimuli preceding a behavior and the consequences following from it to gain a precise understanding of the causes of the behavior.

It is an approach to the study of behavior that involves assessing the frequency of a behavior, the situation in which it occurs, and the reinforcers associated with it. Functional analysis is Skinner's approach to research that involves studying the systematic relationship between behavioral and environmental events. Such study focuses on the relationship between reinforcement contingencies and response rate or response probability. Functional analysis means specifying goals and treatment by assessing antecedents and consequences of a behavior. Analyze what is maintaining the behavior and propose hypotheses about contributors to the behavior. Use this information to guide treatment of the behavior and to further specify goals.