Betty A. Bergstrom

The effect of review on student ability and test efficiency for computerized adaptive tests

The effect of reviewing items and altering responses on the efficiency of computerized adap tive tests and the resultant ability estimates of examinees were explored. 220 students were ran domly assigned to a review condition; their test instructions indicated that each item must be answered when presented, but that the responses could be reviewed and altered at the end of the test. A sample of 492 students did not have the opportunity to review and alter responses. Within the review condition, examinee ability estimates before and after review were correlated .98. The average efficiency of the test was decreased by 1% after review. Approximately 32% of the examinees improved their ability estimates after review, but did not change their pass/fail status. Disallowing review on adaptive tests administered under these rules is not supported by these data.

Computer adaptive testing

The creation of item response theory (IRT) and Rasch models, inexpensive accessibility to high speed desktop computers, and the growth of the Internet, has led to the creation and growth of computerized adaptive testing or CAT. This form of assessment is applicable for both high stakes tests such as certification or licensure exams, as well as health related quality of life surveys. This article discusses the historical background of CAT including its many advantages over conventional (typically paper and pencil) alternatives. The process of CAT is then described including descriptions of the specific differences of using CAT based upon 1-, 2- and 3-parameter IRT and various Rasch models. Numerous specific topics describing CAT in practice are described including: initial item selection, content balancing, test difficulty, test length and stopping rules. The article concludes with the authors reflections regarding the future of CAT.

Computerized Adaptive Testing: Tracking Candidate Response Patterns

Computerized adaptive testing (CAT) uses a computer algorithm to construct and score the best possible individualized or tailored tests for each candidate. The computer also provides an absolute record of all responses and changes to responses, as well as their effects on candidate performance. The detail of the data from computerized adaptive tests makes it possible to track initial responses and response alterations, and their effect on candidate estimated ability measures, as well as the statistical performance of the examination. The purpose of this study was to track the effect of candidate response patterns on a computerized adaptive test. A ninety-item certification examination was divided into nine units of ten items each to track the pattern of initial responses and response alterations on ability estimates and test precision across the nine test units. The precision of the test was affected most by response alterations during early segments of the test. While generally, candidates benefit from altering responses, individual candidates showed different patterns of response alterations across test segments. Test precision is minimally affected, suggesting that the tailoring of CAT is minimally affected by response alterations.