This collection of papers describes research on school and system level change in Chicago's high schools. Papers include "Introduction: Setting Chicago High School Reform within the National Context" (Valerie E. Lee); (1) "The Effort to Redesign Chicago High Schools: Effects on Schools and Achievement" (G. Alfred Hess, Jr. and Solomon Cytrynbaum); (2) "Progress and Problems: Student Performance in CPS High Schools, 1993 to 2000" (Shazia Rafiullah Miller and Elaine M. Allensworth); (3) "Small Schools: Transforming Teacher and Student Experiences in Urban High Schools" (Nicole E. Holland); (4) "Collaborative Learning and Whole School Change at Thomas Jefferson Academy" (Steve Tozer, Connie Yowell, and Richard Gelb); (5) "Teacher Learning Counts: Improving Instruction in One Urban High School through Comprehensive Professional Development" (Joseph Kahne, Connie A. Bridge, and James O'Brien); (6) "Cultural Modeling and the Challenge of Chicago High School Reform" (Carol D. Lee); (7) "Teacher Community, Biography, and Math Reform" (Rochelle Gutierrez and Hector Morales); (8) "Research-Based Reforms Need Strong Implementations: Some Strengths and Weaknesses of Chicago's High School Improvement Program" (James M. McPartland); and (9) "Promises and Problems of Urban School Reform: The Chicago High School Context" (Valerie E. Lee). (Papers contain references.) (SM)