Verbal elaboration of a worked example has been shown to be helpful to learners before attempting to solve similar problems. This has been termed as the self-explanation effect. (Chi, Bassok, Lewis, Reimann & Glaser, 1989). This study examined how self-explanation changes before and after sequential problem solving rounds. We found that changes in self-explanation within an individual may affect individual performance across a series of problem solving episodes. Also, some participants appear to use the worked-out example as a self-generated feedback (SGF) mechanism to help with their problem solving rounds, while other participants do not. Locations or points in a worked-out example where self-explanation (elaboration) is most likely to occur for students with higher performance scores versus those with lower performance scores, is discussed. The implications of these differences for the design of a computational cognitive model are also addressed.