Abstract
This review of transition states considers their significance in the analysis of behavior, along with methodological and empirical issues related to their analysis. Transition states include both transitions from one baseline to another and transitory states, where responding temporarily deviates from otherwise steady-state responding. Transitions are wellsprings of subsequent steady-state behavior, both transitions and transitory states index the effects of variables in steady state conditions preceding and following the transition state, and problems in applied behavior analysis often involve transition states. Methodological challenges of assessing transition states include identifying their beginning and end, establishing appropriate temporal resolutions for their analysis, and their measurement. Variables affecting transition states include parameters of the preceding and following baseline conditions, establishing operations, and behavioral histories. Although historically less studied in behavior analysis than steady-state behavior, understanding behavior in transition is essential in developing behavior theory and its application.