This study served three purposes. The first purpose was to learn what types of activity transitions are difficult for children with autism, the second was to study effects of advanced notice on pausing and challenging behavior during transitions, and the third was to evaluate participant preference for type of transition. Three young men who were students at a residential school for children with autism participated in this study. Study 1 was a descriptive assessment of challenging behavior during transitions between daily activities. For each of the three participants, the highest level of challenging behavior occurred during transitions from high-preference to low-preference activities. Study 2 was an analysis of effects of three different strategies for ending high-preference activities and transitioning to low-preference activities (no notice, advanced notice, and intervening activity). Of primary interest was pausing, the time it took for a participant to comply with an instruction to begin a new activity after the end of the prior activity. Pausing durations during transitions from high-preference to low-preference activities were greatest in the no notice condition, somewhat less in the advanced notice condition, and least in the intervening activity condition. Study 3 was an analysis of preference for the three strategies from Study 2. Participants preferred either the intervening activity or no notice condition; no participant preferred advance notice. These data were presented at APBA 2013, BABAT 2014, CEC-DADD, 2015, NECC ABA for clinicians 2014, ABAI 2015, BABAT 2015, ICEABA 2016.