The Individuals With Disabilities Education Act (IDEA) Amendments of 1997 mandate the use of functional behavioral assessment (FBA) and positive behavioral supports and interventions for students with disabilities. Although much progress has been made in our understanding of functional analysis over the past 15 years, the extent to which these findings can be generalized across clients, methods, settings, and response classes is unknown. This article reviewed 150 school-based intervention studies conducted with children published in the "Journal of Applied Behavior Analysis" from 1991 to 1999. Fifty-two percent of these intervention studies did not report using FBA information linked to the intervention. Interventions based on descriptive, experimental, or combined FBA procedures were no more effective than interventions in which no FBA information was provided. With respect to positive behavioral support, over half of the studies targeted appropriate behaviors with two-thirds of them using a combination of antecedent- and consequence-based interventions. Recommendations are made for conducting fundamental research on reliability and validity issues in FBA and determining when, how, and under what conditions FBA procedures are most appropriate.