The current study adds to a growing body of behavioral research aimed at learning about changes in behavior over time. In this proof-of-concept study, functional analyses were conducted every 6-8 weeks with eight children diagnosed with ASD receiving early intervention services at a community-based clinic. The goal of this study was to develop a method for assessing participants' general sensitivity to common reinforcement contingencies and relative response allocation to problem and appropriate behavior across time. To accomplish this, we reinforced the first instance of either problem behavior or appropriate behavior during functional analyses. Reinforcing appropriate behavior allowed us to fulfill the goals of this study while avoiding deleterious effects on ongoing clinical treatment and ethical concerns about repeatedly exposing participants to assessment contexts that favor problem behavior. The clinical utility of the described approach and avenues for future research are discussed.