ERIC Number: ED475147
Record Type: Non-Journal
Publication Date: 2003-Apr
Reference Count: N/A
A Comparison of Exposure Control Procedures in CAT Systems Based on Different Measurement Models for Testlets Using the Verbal Reasoning Section of the MCAT.
Boyd, Aimee M.; Dodd, Barbara G.; Fitzpatrick, Steven J.
This study compared several item exposure control procedures for computerized adaptive test (CAT) systems based on a three-parameter logistic testlet response theory model (X. Wang, E. Bradlow, and H. Wainer, 2002) and G. Masters' (1982) partial credit model using real data from the Verbal Reasoning section of the Medical College Admission Test. Responses of an average of over 7,000 examinees for each of 22 test forms were used. The exposure control procedures studied were the modified within 0.10 logits procedure (L. Davis and B. Dodd, 2001), the Sympson-Hetter procedure (J. Sympson and R. Hetter, 1985) with a maximum exposure rate restricted to 0.19, the Sympson and Hetter procedure with a maximum exposure rate restricted to 0.29, and maximum information, a no exposure control condition, used as a baseline. The exposure control procedures were evaluated for measurement precision, utilization of the item pool, and item overlap across test administrations. For both measurement models, the modified within 0.10 logits procedure provided better pool utilization, with little decrement in precision of measurement, than either of the Sympson-Hetter procedures. (Contains 8 tables and 27 references.) (Author/SLD)
Publication Type: Reports - Research
Education Level: N/A
Sponsor: Association of American Medical Colleges, Washington, DC.
Authoring Institution: N/A
Identifiers - Assessments and Surveys: Medical College Admission Test