While problem solving is a generally accepted goal of most science courses, it has previously been difficult to determine the extent to which students' problem-solving abilities are impacted by these courses. Interactive Multi-Media Exercises (IMMEX) is a web-based software package that can deliver multiple cases of case-based problems and keep track of the information that students use in solving the problems. Analysis of this tracking data provides insight into the strategies being employed by students. This study uses the IMMEX system to determine the effects of collaborative grouping on the problem-solving strategies of students in first-year chemistry courses. (Contains 4 figures and 2 tables.)