Abstract: The purpose of this qualitative study was to describe teacher perspectives and instructional grouping practices after the implementation of a school improvement model based on Effective Schools research. It addressed the following questions: (a) How did teachers group students for instruction following the implementation of the model? (b) What characterized teacher perspectives regarding instructional grouping practices after implementation of the model? (c) Were those characteristics consistent among schools serving socially and economically diverse student populations? (d) To what extent did the grouping practices and perspectives of teachers become more consistent with the goal of Effective Schools, "teacher for learning for all?" Dissertation Discovery Company and University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, "Teacher Perspectives and Instructional Grouping Practices After District-wide Implementation of a School Improvement Model" by Kathryn Ann Kemmer, was obtained from University of Florida and is being sold with permission from the author. A digital copy of this work may also be found in the university's institutional repository, IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.