Minimizing the influence of item parameter estimation errors in test development: A comparison of three selection procedures

In test development, item response theory (IRT) is a method to determine th e amount of information that each item (i.e., item information function) an d combination of items (i.e., test information function) provide in the est imation of an examinee's ability. Studies investigating the effects of item parameter estimation errors over a range of ability have demonstrated an o verestimation of information when the most discriminating items are selecte d (i.e., item selection based on maximum information). In the present study , the authors examined the influence of item parameter estimation errors ac ross 3 item selection methods-maximum no target, maximum target, and theta maximum-using the 2- and 3-parameter logistic IRT models. Tests created wit h the maximum no target and maximum target item selection procedures consis tently overestimated the test information function. Conversely, tests creat ed using the theta maximum item selection procedure yielded more consistent estimates of the test information function and, at times, underestimated t he test information function. Implications for test development are discuss ed.