The basis for this report is a large research project undertaken by The Ontario Institute for Studies in Education (OISE) for the Ontario Ministry of Education from July 1974 through December 1975. It also uses evidence from two earlier small studies of OISE, from the academic years 1972-73 and 1973-74. The project was designed to be the main research evidence of the Ministry Task Force on Dropouts. The data analyzed in the report are from the sample of 26 school systems drawn from the 9 regions of the province that contain a total of 79 systems. The within year dropout rate for the sample as a whole was 20,027 or 8 percent. Information obtained from the systems about these dropouts included region, age, sex, month of dropout, achievement level, and program. In addition, questionnaires were sent to all the dropouts and returns were received from 8,141 or 41 percent. Finally, telephone interviews were conducted with 423 dropouts in the sample. The task force mandate was to look into the number of dropouts, who they were, where they came from, why they dropped out, what happened to them, and what were their future plans. The aim was to cover all Ontario secondary school students who failed to complete their courses of study as expected. (Author/MLF)