The purpose of this study was to evaluate retention efforts in Ontario (Canada) secondary schools in order to develop policy and support initiatives designed to reduce dropouts and improve retention rates. The study had four parts: (1) an analysis of credit accumulation for four cohorts and academic achievement patterns over 4 years in 16 schools; (2) an examination of eight exemplary programs aimed at students who take mainly general-level courses; (3) an examination of eight exemplary programs for students taking basic-level courses; and (4) an analysis of the extent to which part-time work influences school leaving. The part-time work survey was administered in 13 schools to 4,620 students in grades 11 and above, and the telephone interview was conducted with 610 dropouts from 22 schools. The main findings support the following conclusions: (1) The vast majority of dropouts were taking mainly general-level courses at the time of leaving school, and the students who took mainly basic-level courses were at a particularly high risk of dropping out. (2) The vast majority of dropouts left school because they were so far behind in credit accumulation that the likelihood of graduation was too remote. (3) The fact that students were working more than 20 hours per week had an adverse effect on achievement. (4) There is little evidence that part-time work contributes to the decision of students to leave school early. (5) There is little evidence of a decrease in dropouts occurring because of more relevant programming. (6) There is some evidence that student evaluation emphasizing attendance and work habits contributes to an increase in school retention. (Author/JAM)