The report is based on the results of a mail questionnaire sent to a sample of the total population of persons involved in the registered apprenticeship program in Wisconsin during the years 1965-1970. The returned questionnaires consisted of approximately the same number of dropouts and completers; these two groups were compared throughout the report. The report contains: (1) a review of the literature on apprenticeship with special emphasis on the system in Wisconsin and the dropout, (2) an extensive methodology section which shows the development of the model employed to predict success in apprenticeship programs, (3) a descriptive analysis of the personal, occupational, pre-apprenticeship, post-apprenticeship income and attitudes of the former apprentices, and (4) models predicting success and post-apprenticeship income. (Author)