A 5-year longitudinal study was conducted in Illinois to follow 9,757 of the 10,273 students transferring from two-year colleges to senior colleges and universities in Illinois in fall 1979. The study sought to identify the number and mobility patterns of Illinois two-year college students; to investigate the pre-transfer characteristics of these students; to determine the level of persistence, baccalaureate completion, and performance after transfer; to determine the predictive validity of two-year college grades for senior institution success; and to analyze the relationship between post-transfer achievement and pre-transfer characteristics. Study findings included the following: (1) 31% of the transfer students in the study had earned an Associate in Arts or Associate in Science degree prior to transfer; 7% had earned an Associate in Applied Science degree; and 62% transferred without completing an associate degree; (2) persistence rates and grade point averages (GPA's) tended to increase as the number of two-year college credits transferred increased; (3) 56% of the transfers had earned fewer than 60 semester credit hours at the two-year college from which they transferred; (4) senior college persistence rates and GPA's were higher for students with higher pre-transfer GPA's; (5) there was a significant positive correlation between pre- and post-transfer GPA's regardless of program of study or receiving institution; and (6) students coming from community college pre-transfer agriculture, business, engineering, and communications programs had the highest persistence rates, while students coming from pre-transfer education, arts and humanities, and science and math programs had the highest senior college GPA's. (RO)