This study takes inventory of available evidence on response repetition (RR) effects in task switching, in particular the evidence for RR cost when the task switches. The review reveals that relatively few task-switching studies in which RR effects were addressed have shown statistical support for RR cost, and that almost all are affected by 1 of 2 potential artifacts, either a response bias caused by disallowing stimulus repetitions or the effect of including stimulus repetitions in data analysis. New results with these factors controlled support an episodic retrieval model in which features of the retrieved trace, including the stimulus but also the task, task cue, and response, facilitate or interfere with performance depending on whether they match or mismatch the current processing context. (Contains 5 figures, 4 tables, and 2 footnotes.)