Investigating faking using a multilevel logistic regression approach to measuring person fit

This article describes how a multilevel logistic regression (MLR) approach to assessing person fit can be used to test hypotheses concerning faking on personality assessments. Item difficulty and person trait estimates obtained from a two-parameter logistic item response theory model are used to predict the probability of endorsing an item in a MLR equation. The regression slope for item difficulty reflects the extent to which the probability of endor-sement decreases as item difficulty increases. Less negative slopes may indicate faking, and slope variance may be modeled with person-level variables using MLR. Two examples are presented. Example 1 models faking on a personality assessment with dichotomous items. Example 2 extends the approach to scales using polytomous items