The current study was designed to evaluate the utility of progressing sequentially from multiple-respondent anecdotal assessments through test-control treatment analysis as an effective and efficient method of identifying the environmental determinants of problem behavior. the goal of the study was to evaluate overall agreement among multiple respondents on the primary function of aberrant behavior using the Motivation Assessment Scale (MAS) and Questions About Behavioral Function (QABF) and, if agreement was obtained, conduct a test-control evaluation to confirm anecdotal assessment findings while simultaneously evaluating the effects of function-based treatment. for 4 individuals, at least 4 of 5 respondents to the anecdotal assessments agreed (both within and across assessments) on the probable maintaining consequence for their problem behaviors. Test-control multielement evaluations were then conducted in which baseline sessions, corresponding to the suspected operant function of each individual’s problem behavior, were alternated with sessions in which the identified contingency was arranged for alternative behavior. Each evaluation showed substantial decreases in problem behavior and maintenance of alternative responses.