This report evaluates New York City's Summer High School Preparation for Raising Educational Performance (PREP) program, which was designed to ease Chapter 1-eligible students' transition from junior to senior high school. The report contains the following: (1) an introduction with information on program background, objectives, and methodology; (2) information on program implementation, including staffing, student recruitment, and counseling; (3) assessment of program outcome; (4) results of a student attitude survey; and (5) conclusions and recommendations. Summer PREP operated in 1985 for 22 days at 45 high schools. It targeted incoming ninth and tenth grade students scoring two or more years below grade level on nationally normed reading or mathematics tests, as well as limited English proficient and special education students. Pupils received three hours of instruction daily. Afternoon sessions included trips and other special activities. According to the assessment, PREP's goal that 70 percent of participants demonstrate improvement on norm-referenced reading and mathematics tests was not met. Students' attitudes toward school were initially positive and remained so. It is recommended that recruitment should begin earlier in the spring; use of student mentors should be continued and their roles expanded; and program assessment methods should be reconsidered. (PS)