A Framework for Measuring the Amount of Adaptation of Rasch‐based Computerized Adaptive Tests. Issue 1 (18th February 2020)

• Record Type: Journal Article
• Authors: Wyse, Adam E.; McBride, James R.
• Is Part Of: Journal of educational measurement. Volume 58:Issue 1(2021)
• Page Start: 83
• Page End: 103
• Publication Date: 2020-02-18
• Subjects: Educational tests and measurements -- Periodicals; 371.2605
• DOI: 10.1111/jedm.12267
• Languages: English
• ISSNs: 0022-0655

Abstract

Abstract: A key consideration when giving any computerized adaptive test (CAT) is how much adaptation is present when the test is used in practice. This study introduces a new framework to measure the amount of adaptation of Rasch‐based CATs based on looking at the differences between the selected item locations (Rasch item difficulty parameters) of the administered items and target item locations determined from provisional ability estimates at the start of each item. Several new indices based on this framework are introduced and compared to previously suggested measures of adaptation using simulated and real test data. Results from the simulation indicate that some previously suggested indices are not as sensitive to changes in item pool size and the use of constraints as the new indices and may not work as well under different item selection rules. The simulation study and real data example also illustrate the utility of using the new indices to measure adaptation at both a group and individual level. Discussion is provided on how one may use several of the indices to measure adaptation of Rasch‐based CATs in practice.