01505nas a2200157   4500008003900000022001400039245008900053210006900142300001200211490000700223520101800230100001701248700001501265700002601280856004101306       2015                          d  a1745-398400aA Comparison of IRT Proficiency Estimation Methods Under Adaptive Multistage Testing0 aComparison of IRT Proficiency Estimation Methods Under Adaptive   a70–790 v523 aThis inquiry is an investigation of item response theory (IRT) proficiency estimators’ accuracy under multistage testing (MST). We chose a two-stage MST design that includes four modules (one at Stage 1, three at Stage 2) and three difficulty paths (low, middle, high). We assembled various two-stage MST panels (i.e., forms) by manipulating two assembly conditions in each module, such as difficulty level and module length. For each panel, we investigated the accuracy of examinees’ proficiency levels derived from seven IRT proficiency estimators. The choice of Bayesian (prior) versus non-Bayesian (no prior) estimators was of more practical significance than the choice of number-correct versus item-pattern scoring estimators. The Bayesian estimators were slightly more efficient than the non-Bayesian estimators, resulting in smaller overall error. Possible score changes caused by the use of different proficiency estimators would be nonnegligible, particularly for low- and high-performing examinees.1 aKim, Sooyeon1 aMoses, Tim1 aYoo, Hanwook, (Henry)  uhttp://dx.doi.org/10.1111/jedm.12063