| Abstract: | Performance assessments, scenario‐based tasks, and other groups of items carry a risk of violating the local item independence assumption made by unidimensional item response theory (IRT) models. Previous studies have identified negative impacts of ignoring such violations, most notably inflated reliability estimates. Still, the influence of this violation on examinee ability estimates has been comparatively neglected. It is known that such item dependencies cause low‐ability examinees to have their scores overestimated and high‐ability examinees' scores underestimated. However, the impact of these biases on examinee classification decisions has been little examined. In addition, because the influence of these dependencies varies along the underlying ability continuum, whether or not the location of the cut‐point is important in regard to correct classifications remains unanswered. This simulation study demonstrates that the strength of item dependencies and the location of an examination systems’ cut‐points both influence the accuracy (i.e., the sensitivity and specificity) of examinee classifications. Practical implications of these results are discussed in terms of false positive and false negative classifications of test takers. |
