Functional analysis: what have we learned in 85 years?

Even though the term "functional analysis" (FA) is prevalent in the current behavioral literature, the concept and process have roots in the early days of basic research in behavior analysis. Furthermore, the methodology developed in the field of FA has been one of the most significant advances in research on challenging behaviors over the past four decades. The current article reviews the history of the term "functional analysis" and research related to experimental FA. The aim is to summarize what the field of behavior analysis has learned about this powerful methodology.

FA is considered a gold standard of functional assessment. However, several arguments about limitations relating to methodological issues in FA and its ecological validity have been put forward. Some of these shortcomings include constraints on the time available for assessment, the risk posed by severe problem behavior, and the inability to exert tight control over environmental conditions.

The literature on the subject clearly shows that refinements have been aimed not only at improving some of the methodological characteristics of FA but also at adapting the strategy for real-world application. Practical functional assessment (known as interview-informed synthesized contingency analysis [IISCA]) is a contemporary approach to assessing and treating problem behavior. Recent research on IISCA offers empirical support for the practical functional assessment and skill-based treatment model, confirming that it can obtain sustainable and socially meaningful reductions in problem behavior. Nevertheless, more research is needed to address procedural variations in, and the utility and social validity of, IISCA.