Validity evidence based on test content is important for educational tests to demonstrate the degree to which they fulfill their purposes. Most content validity studies involve subject matter experts (SMEs) who rate items that comprise a test form. In computerized-adaptive testing, examinees take different sets of items and test "forms"…

The PEDI-CAT is a new computer adaptive test (CAT) version of the Pediatric Evaluation of Disability Inventory (PEDI). Additional PEDI-CAT items specific to postacute pediatric hospital care were recently developed using expert reviews and cognitive interviewing techniques. Expert reviews established face and construct validity, providing positive…

The effects of using item response theory (IRT) ability estimates based on customized tests formed by selecting areas from a nationally standardized achievement test were examined. For some populations, in some conditions, IRT ability estimates can be equivalent to scores based on full-length tests. (SLD)