Accounting for Aberrant Test Response Patterns Using Multilevel Models

Hypotheses about aberrant test‐response behavior and hence invalid person‐measurement have hitherto included factors like ability, gender, language, test‐anxiety, and motivation, but these have not previously been collectively investigated with real data, or with multilevel models. This study analyzes the effect of these factors on person aberrance using a real mathematics assessment data set under the framework of a two‐level (person and classroom) hierarchical model. The results suggest that higher‐scoring pupils, and, to a lesser extent, second‐language learners are significantly more often aberrant. But more importantly, we find that the classroom makes a significant contribution to person aberrance and conclude that studies that investigate the sources of person aberrance with real data should model the classroom as well as individual levels.