Experiments on factors affecting intrinsic motivation have generally inferred intrinsic motivation from subjects' engagement in a target activity during a "free-choice period" when external contingencies are no longer operative. However, internally controlling regulation is a form of internal motivation that is very different from intrinsic motivation and can underlie free-choice-period activity. This paper presents three experiments concerned with differentiating internally controlling from intrinsically motivated persistence in situations where ego-involved vs. task-involved subjects had received positive vs. nonconfirming (or no) performance feedback. The first experiment showed that ego-involved (relative to task-involved) subjects displayed less free-choice persistence when they received positive feedback, whereas the second experiment showed that ego-involved (relative to task-involved) subjects displayed more free-choice persistence when they received nonconfirming feedback. In both experiments, however, it was shown that ego-involved subjects did not report the expected affective correlates of intrinsic motivation-namely, interest/enjoyment and perceived choice-whereas task-involved subjects did. In the third experiment, as predicted, ego-involved subjects tended to show less free-choice persistence than task-involved subjects when they received positive performance feedback but greater free-choice persistence when they received no performance feedback. The problem of distinguishing intrinsically motivated activity from internally controlled behavior is discussed.