This study demonstrates the potential for collaborative research among participants in local settings to effect positive change in urban settings characterized by diversity. It describes an interpretive case study of a racially, ethnically, and socioeconomically diverse eighth grade science classroom in an urban magnet school in order to explore why some of the students did not achieve at high levels and identify with school science although they were both interested in and knowledgeable about science. The results of this study indicated that structural issues such as the school's selection process, the discourses perpetuated by teachers, administrators, and peers regarding "who belongs" at the school, and negative stereotype threat posed obstacles for students by highlighting rather than mitigating the inequalities in students' educational backgrounds. We explore how a methodology based on the use of cogenerative dialogues provided some guidance to teachers wishing to alter structures in their classrooms to be more conducive to all of their students developing identities associated with school science. Based on the data analysis, we also argue that a perspective on classrooms as communities of practice in which learning is socially situated rather than as forums for competitive displays, and a view of students as valued contributors rather than as recipients of knowledge, could address some of the obstacles. Recommendations include a reduced emphasis on standardized tasks and hierarchies, soliciting unique student contributions, and encouraging learning through peripheral participation, thereby enabling students to earn social capital in the classroom. (Contains 2 notes.)