The limited research that exists in the area of prior learning assessment (PLA) has tended to be descriptive and conceptual in nature. Where empirical studies have been done, they have focussed mainly on PLA as a means of credentialing rather than as a learning experience. Furthermore, there has been very little empirical research into the educational effectiveness of PLA from the student's point of view. This empirical study used a qualitative approach to investigate the perceptions of a focus group of 32 adult learners who were engaged in portfolio-based PLA in an open and distance-education university. The study explored students' initial expectations of PLA, what they think they got out of the process, and the extent to which these perceived benefits of PLA would extend to other adult students. The study examined the question of whether PLA operates as a motivator or as a selection mechanism and concluded that there was evidence for both factors. Further results indicated that, in general, PLA learners were surprised to find they had been engaged in a learning process. The study concludes that PLA can be an effective educational opportunity for certain kinds of adult learners, but it should not be taken as a panacea. (Contains 1 table and 6 endnotes.)