Increasing recent research on nontraditional students has uncovered anomalies and inconsistencies in Tinto's model of student persistence patterns, especially with regard to academic and social integration. It is hypothesized that these inconsistencies are a product of the heterogeneous nature of nontraditional student populations, combined with limited methodological approaches utilizing undifferentiated student tracking and standardized surveys. This hypothesis was tested through the use of selected case studies. A sample of 20 students was drawn from the approximately 140 respondents to a 1986-87 followup survey of a group of students placed in a Guided Studies program in the fall of 1984. Personal interviews, preceded by a questionnaire on all aspects of academic and social integration, were conducted to identify and define variables associated with student success. Findings were found to be consistent with Tinto's model and inconsistent with recent research on nontraditional students. The use of the case study approach, instead of aggregate quantitative methodology, and the focus on academically underprepared students, rather than a larger student population, are given as probable reasons for the differences. Contains 18 references. (Author/KM)