This document reviews research on the factors affecting the retention of adult students, discusses the relevance of some attrition models for adults, and presents strategies for helping adults adapt to the university and for adapting the university to adults. Reviewing factors affecting retention, the digest says that student characteristics, circumstances, and the educational environment affect adult students' persistence and participation in higher education and suggests that since educators have so little influence over the first two of those factors, they had better concentrate on the third. Among the writers cited are those who believe that educational institutions are "out of sync" with adult students, that many adults attend school for reasons other than obtaining academic degrees (making "degree obtained" an irrelevant measure of persistence), and that institutions have taken three approaches toward adult programs (only one of which places the programs in the mainstream of the institution). The most relevant implications of several retention studies are presented in a review of retention models and adult students. A section on helping adults adapt to the university lists situational factors and psychological influences that affect persistence, as well as services and interventions that can help alleviate problems. The section on adapting the university to adult students lists eight program and instructional strategies to enhance retention and five techniques aimed at making the institutional environment more flexible. Eleven references appear. (CML)