In 1998, the Chicago Public Schools piloted the Chicago Academic Standards Exam (CASE) to assess how well students had learned the content and processes delineated in the Chicago Academic Standards (CAS) and Frameworks. This report examines the implementation of district curricular standards and assessments and the effects on teaching in four high schools. Researchers collected district-level curricular standards, materials concerning the CASE given to schools and teachers, and the district's Programs of Study. They interviewed central office administrators involved in developing and implementing the standards and assessments and teachers and administrators at the four schools regarding their responses to the CAS and CASE. They observed teachers at each school teach the same lesson and gathered work from high- and low-achieving students in those classes. Results indicated that district-wide standards in English represented multiple curricular and instructional goals; stated goals were displaced as standards were translated into the Programs of Study and CASE; teachers' curricular decisions and instructional choices were very similar across schools; teachers responded most to regulatory aspects of the standards and assessments (with the CASE exam structuring the curriculum); and teachers received only limited professional development regarding the standards and assessments. (Contains 17 tables and 18 endnotes.) (SM)