Implications of test revisions for research.

Test revisions are increasingly common in psychology and neuropsychology in particular. However, such revisions may alter in complex ways the kind of information obtained, and they may assess traits, abilities, and conditions in ways different from earlier versions. This article outlines some of the problems associated with the revision of tests facing clinicians and researchers. Three broad classes of revision are considered. Part 1 considers the aging of tests, part 2 concerns the aging of participants, and part 3 considers changes in test format. Although the article focuses largely on measures of intelligence and personality, the issues addressed in the article apply to other tests and assessment domains as well.