Investigating the Psychometric Impact of Negative Worded Items in Reading Comprehension Passages with a 3PL Cross-Classified Testlet Model

Abstract

Negative worded (NW) items used in psychological instruments have been studied with the bifactor model to investigate whether the NW items form a secondary factor due to negative wording orthogonal to the measured latent construct, a validation procedure which checks whether NW items form a source of construct irrelevant variance (CIV) and hence constitute a validity threat. In the context of educational testing, however, no such validation attempts have been made. In this study, we studied the psychometric impact of NW items in an English proficiency reading comprehension test using a modeling approach similar to the bifactor model, namely the three-parameter logistic cross-classified testlet response theory (3PL CCTRT) model, to account for both guessing and possible local item dependence due to passage effect in the data set. The findings indicate that modeling the NW items with a separate factor leads to noticeable improvement in model fit, and the factor variance is marginal but nonzero. However, item and ability parameter estimates are highly similar between the 3PL CCTRT model and other models that do not model the NW items. It is concluded that the NW items introduce CIV into the data, but its magnitude is too small to change item and person ability parameter estimates to an extent of practical significance.