Two studies of influences on self-regulated performance were conducted. The purpose of the first was to determine if the level of performance of college students would be higher if the allowable length of the assignment was greater or smaller. Subjects were 126 education majors at a large state university participating in an extra-credit program called the Voluntary Homework System (VHS) as part of a course in educational psychology. The maximum number of test items prepared for extra credit that could be submitted each week was set at 100 for one group and 25 for a second group. Students gave self reports of their own competence. Analysis of variance indicated that length limit and perceived self-competence level affected performance, with a significantly lower level of performance produced by the 100-item limit. In a second study, 63 students from the same course had a 25-item length limit and were graded according to preset criteria of 300 points for a single bonus and 450 points for a double bonus. Other aspects of the VHS were identical. The grading criteria tended to affect performance differently for the different self-competence levels. Its overall impact was not great, but students low in perceived self-competence tended to receive the greatest motivational boost. Implications for instruction are discussed. Four tables present study data. (SLD)