Multistage Computerized Adaptive Testing With Uniform Item Exposure

This article describes a computerized adaptive test (CAT) based on the uniform item exposure multi-form structure (uMFS). The uMFS is a specialization of the multi-form structure (MFS) idea described by Armstrong, Jones, Berliner, and Pashley (1998 Armstrong, R. D., Jones, D. H., Berliner, N. and Pashley, P. June 1998. Computerized adaptive tests with multiple form structures, June, Champaign-Urbana, IL: Paper presented at the annual meeting of the Psychometric Society. [Google Scholar]). In an MFS CAT, the examinee first responds to a small fixed block of items. The items comprising that block may be unrelated to each other, or they may comprise a testlet (Wainer and Kiely, 1987 Wainer, H. and Kiely, G. L. 1987. Item clusters and computerized adaptive testing: A case for testlets. Journal of Educational Measurement, 24: 185–201. [Crossref], [Web of Science ®] , [Google Scholar]) After the first block of items has been administered, adaptation takes place in the choice of the next block to be administered and subsequent blocks. The uMFS design integrates item exposure control, as well as content balancing and other test development needs, into the design of the CAT, instead of placing those activities in the online implementation. We show that it is possible to implement item exposure control, in a very thorough way, in the psychometric specifications of the item blocks.