A research-based framework for teaching science is a heuristic tool used to help preservice teachers conceptualize many complexities of teaching while making explicit the strategy to use a research-based body of professional knowledge to inform instructional decision-making (Clough, 2003, Paper presented at the annual meeting of the Association for the Education of Teachers in Science, St. Louis, MO). Elementary preservice teachers frequently struggle to apply this knowledge to classroom decisions (Madsen, 2002, Paper presented at the annual meeting of the North Central Association for the Education of Teachers of Science, Bettendorf, IA). This study examined the effects of using a video case-analysis within an elementary science methods course focused on the development of a research-based framework. Students in two course sections completed a unit plan, and students in one section completed the video analysis. Video analysis students' performance on an oral defense with the instructor was compared with oral defense performance from students in the unit plan group. Video analysis students outperformed their peers on questions related to how learning theories influence decisions of selecting content, explaining the use of questioning, and the use of self assessment strategies. Despite these differences, students in both groups still perceive teaching as primarily accomplished through activities and have difficulties understanding the critical role of the teacher in promoting student goals. This study raises issues regarding teachers' knowledge development during preservice experiences.