Supplemental Instruction is an academic assistance program that utilizes peer-assisted study sessions. The SI sessions are regularly-scheduled informal review sessions in which students compare their class notes, discuss assigned readings, practice problem solving, develop organizational tools, and predict test items. The participants learn how to integrate course content and study skills while working together. The sessions are facilitated by -SI leaders, students who have previously taken the courses and done well in them. The SI leaders also attend all the lectures, take notes, and are model students. The main purposes of this program are to advance students' comprehension of the course material, increase grades and imrove student graduation rates.