The followup study of 1974 graduates of two Pennsylvania high school districts (Hazleton and Williamsport) is phase 4 of the vocational development study, a 10-year longitudinal study begun in 1968. Phase 4 evaluates the effectiveness of the school programs in preparing students for the world of work or for postsecondary education and examines the vocational development process. Socioeconomic background information is provided for Hazelton and Williamsport and further describes the population sample who were first studied as freshmen. Mailing of followup questionnaires was begun in March 1975, with all sampling (including a telephone followup) completed by June 30, 1975. The collection strategy is diagrammed and response data, analysis, and discussion of responses are given. Explanation of the data coding, storage, and tape layout systems are provided. With data from the overall longitudinal study other research has been undertaken. Appended are five convention papers that reflect this research: (1) "Path Analysis and Vocational Education Research: An Overview"; (2) "Patterns Related to Employment Satisfaction: A Casual Model Analysis"; (3) "Path Analysis and Vocational Development Research"; (4) "Path Analysis: An Investigation of Stability of Expressed Occupational Choice"; and (5) "Ovis Two-Year Stability: Grade 9-Grade 11--(Pennsylvania Sample)." Ohio Vocational Interest Survey, Special Report Series, Report No. 4, November 1974. (KH)