ABSTRACT
Computerized adaptive testing (CAT) greatly improves measurement efficiency in high-stakes testing operations through the selection and administration of test items with the difficulty level that is most relevant to each individual test taker. This paper explains the 3 components of a conventional CAT item selection algorithm: test content balancing, the item selection criterion, and item exposure control. Several noteworthy methodologies underlie each component. The test script method and constrained CAT method are used for test content balancing. Item selection criteria include the maximized Fisher information criterion, the b-matching method, the a-stratification method, the weighted likelihood information criterion, the efficiency balanced information criterion, and the Kullback-Leibler information criterion. The randomesque method, the Sympson-Hetter method, the unconditional and conditional multinomial methods, and the fade-away method are used for item exposure control. Several holistic approaches to CAT use automated test assembly methods, such as the shadow test approach and the weighted deviation model. Item usage and exposure count vary depending on the item selection criterion and exposure control method. Finally, other important factors to consider when determining an appropriate CAT design are the computer resources requirement, the size of item pools, and the test length. The logic of CAT is now being adopted in the field of adaptive learning, which integrates the learning aspect and the (formative) assessment aspect of education into a continuous, individualized learning experience. Therefore, the algorithms and technologies described in this review may be able to help medical health educators and high-stakes test developers to adopt CAT more actively and efficiently.
ABSTRACT
Computerized adaptive testing (CAT) technology is widely used in a variety of licensing and certification examinations administered to health professionals in the United States. Many more countries worldwide are expected to adopt CAT for their national licensing examinations for health professionals due to its reduced test time and more accurate estimation of a test-taker's performance ability. Continuous improvements to CAT algorithms promote the stability and reliability of the results of such examinations. For this reason, conducting simulation studies is a critically important component of evaluating the design of CAT programs and their implementation. This report introduces the principles of SimulCAT, a software program developed for conducting CAT simulation studies. The key evaluation criteria for CAT simulation studies are explained and some guidelines are offered for practitioners and test developers. A step-by-step tutorial example of a SimulCAT run is also presented. The SimulCAT program supports most of the methods used for the 3 key components of item selection in CAT: the item selection criterion, item exposure control, and content balancing. Methods for determining the test length (fixed or variable) and score estimation algorithms are also covered. The simulation studies presented include output files for the response string, item use, standard error of estimation, Newton-Raphson iteration information, theta estimation, the full response matrix, and the true standard error of estimation. In CAT simulations, one condition cannot be generalized to another; therefore, it is recommended that practitioners perform CAT simulation studies in each stage of CAT development.
ABSTRACT
Computerized adaptive testing (CAT) greatly improves measurement efficiency in high-stakes testing operations through the selection and administration of test items with the difficulty level that is most relevant to each individual test taker. This paper explains the 3 components of a conventional CAT item selection algorithm: test content balancing, the item selection criterion, and item exposure control. Several noteworthy methodologies underlie each component. The test script method and constrained CAT method are used for test content balancing. Item selection criteria include the maximized Fisher information criterion, the b-matching method, the a-stratification method, the weighted likelihood information criterion, the efficiency balanced information criterion, and the Kullback-Leibler information criterion. The randomesque method, the Sympson-Hetter method, the unconditional and conditional multinomial methods, and the fade-away method are used for item exposure control. Several holistic approaches to CAT use automated test assembly methods, such as the shadow test approach and the weighted deviation model. Item usage and exposure count vary depending on the item selection criterion and exposure control method. Finally, other important factors to consider when determining an appropriate CAT design are the computer resources requirement, the size of item pools, and the test length. The logic of CAT is now being adopted in the field of adaptive learning, which integrates the learning aspect and the (formative) assessment aspect of education into a continuous, individualized learning experience. Therefore, the algorithms and technologies described in this review may be able to help medical health educators and high-stakes test developers to adopt CAT more actively and efficiently.
Subject(s)
Animals , Cats , Humans , Education , Health Educators , Learning , Logic , Methods , Patient Selection , Retinoscopy , Test Taking SkillsABSTRACT
Computerized adaptive testing (CAT) technology is widely used in a variety of licensing and certification examinations administered to health professionals in the United States. Many more countries worldwide are expected to adopt CAT for their national licensing examinations for health professionals due to its reduced test time and more accurate estimation of a test-taker's performance ability. Continuous improvements to CAT algorithms promote the stability and reliability of the results of such examinations. For this reason, conducting simulation studies is a critically important component of evaluating the design of CAT programs and their implementation. This report introduces the principles of SimulCAT, a software program developed for conducting CAT simulation studies. The key evaluation criteria for CAT simulation studies are explained and some guidelines are offered for practitioners and test developers. A step-by-step tutorial example of a SimulCAT run is also presented. The SimulCAT program supports most of the methods used for the 3 key components of item selection in CAT: the item selection criterion, item exposure control, and content balancing. Methods for determining the test length (fixed or variable) and score estimation algorithms are also covered. The simulation studies presented include output files for the response string, item use, standard error of estimation, Newton-Raphson iteration information, theta estimation, the full response matrix, and the true standard error of estimation. In CAT simulations, one condition cannot be generalized to another; therefore, it is recommended that practitioners perform CAT simulation studies in each stage of CAT development.