ABSTRACT
The scienti®c philosophy upon which BA techniques are based has evolved from early writings on radical behaviorism by B. F. Skinner (1953, 1974) to functional contextualism by Steve Hayes (Gifford and Hayes, 1999; Hayes, 1993; Hayes, Hayes, Reese, & Sarbin, 1988). In developing functional contextualism, Hayes in essence critically evaluated the scienti®c philosophy of radical behaviorism advanced by Skinner, which had been very successful as a framework for basic non-human behavioral research and applied behavioral interventions in controlled settings (e.g., residential settings), but less successful as a framework for the development of interventions for adult, outpatient populations. Hayes clari®ed, elaborated, reformulated, and repackaged the important themes from this early philosophical system, stripping away some of the jarring and polemical aspects of Skinner's work and distilling the core elements that are important to adult, outpatient populations. BA may be seen as based on functional contextualism, but some behaviorists may instead consider it a radical behavioral, or behavior-analytic, approach.
