The general objective of a research program on adaptive testing was to identify several sources of potential error in test scores, and to study adaptive testing as a means for reducing these errors. Errors can result from the mismatch of item difficulty to the individual's ability; the psychological effects of testing and the test environment; the inability to extract enough information from the testee's response; deviations from unidimensionality; and an oversimplistic conceptualization of ability. Several different strategies of adaptive testing are discussed, along with the information level they yield, and the bias that can result from various scoring methods. In a discussion of the unidimentionality of test items, the consistency of the testee's response is analyzed. Finally, group differences are examined in terms of the psychological effects of receiving immediate feedback, especially on low ability groups. The author concludes that adaptive testing and immediate knowledge of results may be able to provide testing conditions more conclusive to each person's ability to demonstrate his/her fullest capacities in test performance. (Author/BW)