@article {2304, title = {A Comparison of Exposure Control Procedures in CATs Using the 3PL Model}, journal = {Educational and Psychological Measurement}, volume = {73}, number = {5}, year = {2013}, pages = {857-874}, abstract = {

This study compares the progressive-restricted standard error (PR-SE) exposure control procedure to three commonly used procedures in computerized adaptive testing, the randomesque, Sympson\–Hetter (SH), and no exposure control methods. The performance of these four procedures is evaluated using the three-parameter logistic model under the manipulated conditions of item pool size (small vs. large) and stopping rules (fixed-length vs. variable-length). PR-SE provides the advantage of similar constraints to SH, without the need for a preceding simulation study to execute it. Overall for the large and small item banks, the PR-SE method administered almost all of the items from the item pool, whereas the other procedures administered about 52\% or less of the large item bank and 80\% or less of the small item bank. The PR-SE yielded the smallest amount of item overlap between tests across conditions and administered fewer items on average than SH. PR-SE obtained these results with similar, and acceptable, measurement precision compared to the other exposure control procedures while vastly improving on item pool usage.

}, doi = {10.1177/0013164413486802}, url = {http://epm.sagepub.com/content/73/5/857.abstract}, author = {Leroux, Audrey J. and Lopez, Myriam and Hembry, Ian and Dodd, Barbara G.} } @article {2193, title = {Comparison of Exposure Controls, Item Pool Characteristics, and Population Distributions for CAT Using the Partial Credit Model}, journal = {Educational and Psychological Measurement}, volume = {72}, number = {1}, year = {2012}, pages = {159-175}, abstract = {

This study investigated item exposure control procedures under various combinations of item pool characteristics and ability distributions in computerized adaptive testing based on the partial credit model. Three variables were manipulated: item pool characteristics (120 items for each of easy, medium, and hard item pools), two ability distributions (normally distributed and negatively skewed data), and three exposure control procedures (randomesque procedure, progressive\–restricted procedure, and maximum information procedure). A number of measurement precision indexes such as descriptive statistics, correlations between known and estimated ability levels, bias, root mean squared error, and average absolute difference, exposure rates, item usage, and item overlap were computed to assess the impact of matched or nonmatched item pool and ability distributions on the accuracy of ability estimation and the performance of exposure control procedures. As expected, the medium item pool produced better precision of measurement than both the easy and hard item pools. The progressive\–restricted procedure performed better in terms of maximum exposure rates, item average overlap, and pool utilization than both the randomesque procedure and the maximum information procedure. The easy item pool with the negatively skewed data as a mismatched condition produced the worst performance.

}, doi = {10.1177/0013164411411296}, url = {http://epm.sagepub.com/content/72/1/159.abstract}, author = {Lee, HwaYoung and Dodd, Barbara G.} } @article {2161, title = {A Comparison of Item Selection Techniques for Testlets}, journal = {Applied Psychological Measurement}, volume = {34}, number = {6}, year = {2010}, pages = {424-437}, abstract = {

This study examined the performance of the maximum Fisher\’s information, the maximum posterior weighted information, and the minimum expected posterior variance methods for selecting items in a computerized adaptive testing system when the items were grouped in testlets. A simulation study compared the efficiency of ability estimation among the item selection techniques under varying conditions of local-item dependency when the response model was either the three-parameter-logistic item response theory or the three-parameter-logistic testlet response theory. The item selection techniques performed similarly within any particular condition, the practical implications of which are discussed within the article.

}, doi = {10.1177/0146621609349804}, url = {http://apm.sagepub.com/content/34/6/424.abstract}, author = {Murphy, Daniel L. and Dodd, Barbara G. and Vaughn, Brandon K.} } @article {2143, title = {Computerized Adaptive Testing With the Partial Credit Model: Estimation Procedures, Population Distributions, and Item Pool Characteristics}, journal = {Applied Psychological Measurement}, volume = {29}, number = {6}, year = {2005}, pages = {433-456}, abstract = {

The primary purpose of this research is to examine the impact of estimation methods, actual latent trait distributions, and item pool characteristics on the performance of a simulated computerized adaptive testing (CAT) system. In this study, three estimation procedures are compared for accuracy of estimation: maximum likelihood estimation (MLE), expected a priori (EAP), and Warm\&$\#$39;s weighted likelihood estimation (WLE). Some research has shown that MLE and EAP perform equally well under certain conditions in polytomous CAT systems, such that they match the actual latent trait distribution. However, little research has compared these methods when prior estimates of. distributions are extremely poor. In general, it appears that MLE, EAP, and WLE procedures perform equally well when using an optimal item pool. However, the use of EAP procedures may be advantageous under nonoptimal testing conditions when the item pool is not appropriately matched to the examinees.

}, doi = {10.1177/0146621605280072}, url = {http://apm.sagepub.com/content/29/6/433.abstract}, author = {Gorin, Joanna S. and Dodd, Barbara G. and Fitzpatrick, Steven J. and Shieh, Yann Yann} }