One of the hallmarks of adolescent and adult development of expert performance is its self regulation. This paper reviews different approaches to assessing the use of self-regulated learning (SRL) strategies in high- school and college students and their ability to predict academic performance. The current study assesses the use of SRL strategies with interviews and diaries and their relation to grade point average (GPA) in sixty upper-level college students majoring in science. Their diaries revealed that students with high, aver- age, and low GPAs (assessed before the start of the semester) differed in overall use of SRL strategies and in the use of particular strategies during specific weeks. Methods of assessing and understanding differences in adult self-regulation and subsequent academic performance are evaluated and discussed.