Issues on functional analysis in behavioral assessment

The rebirth of interest in functional analysis is described. Clarification among conflicting terms is offered as a way of facilitating research in the area. Three phases of functional approach to assessment are identified: (a) descriptive, (b) interpretive, and (c) verification. Five assessment methods common to assessment, generally, are shown to be useful in both descriptive and verification phases. Evaluation of functional approaches requires attention to the psychometric adequacy of these methods. Accuracy, reliability, and validity concepts are reviewed briefly and their application to functional strategies is described. The use of treatment validity in the functional analysis of functional analysis is mentioned as the ultimate strategy for evaluating the adequacy of this assessment approach. The paper ends with a discussion of problems of multiple control of behavior, behavioral classification systems, training parents and other mediators in the functional approach, cost-effectiveness, and the place of functional analysis in a reorganized health care delivery system.