9731428 Silver The COMET Project is dedicated to the creation and dissemination of professional development materials in middle school mathematics. This project, directed by Dr. Edward Silver and located at the University of Pittsburgh, with a subcontract with Dr. Margaret Smith at The Pennsylvania State University, involves the development of sixteen cases, each involving a classroom lesson in which an important idea in middle school mathematics (grades 6-8) is linked with a cognitively challenging task. The cases will be developed in four clusters; with about four cases in each cluster, each related to an important mathematics topic. Tentative clusters include: solving measurement problems in two and three dimensions; solving problems related to algebra as the study of patterns and functions; solving problems involving reasoning with rates, ratios, and proportions; and solving problems involving the representation and analysis of statistical data in numerical and graphical forms. The project cases will involve the use of materials and experiences generated by the QUASAR Project. In addition, the project will involve NSF-funded implementation centers (the University of Missouri and EDC sites) and NSF-funded curriculum projects (Connected Mathematics, Mathematics in Context, and Visual Mathematics) as field sites for the implementation of the cases. The uniqueness of this project is in the use of cases based on actual practice and a strong research base and dealing with the middle school mathematics curriculum. COMET will organize and host a small conference (to be held at NSF) on cases and their use in the enhancement of teacher content and professional knowledge in the first year of the project. Additionally, the project's evaluation will include a formative evaluation of the extent to which the COMET cases have impacted the content and professional knowledge of the project's field test participants (middle school teachers).