This study compares the discussion participation and performance of 7 undergraduate students enrolled in an e-commerce programming course during the spring semester of 2010 to that of 13 students enrolled in the same course during fall of that year. In the former course, the instructor participated in the required discussion only at the very end of the discussion period; in the latter, the instructor was an active participant at least once during the middle and once before the end of the discussion period. Students' discussion participation level was measured by their message-posting rate, and student performance was measured in terms of their scores on assignments. Results showed that the frequency and promptness of instructor participation have no effect on student participation or performance in online classes.