Research shows that test method can exert a significant impact on test takers' performance and thereby contaminate test scores. We argue that common test method can exert the same effect as common stimuli and violate the conditional independence assumption of item response theory models because, in general, subsets of items which have a shared…

This paper examines the uptake of Rasch measurement in language testing through a consideration of research published in language testing research journals in the period 1984 to 2009. Following the publication of the first papers on this topic, exploring the potential of the simple Rasch model for the analysis of dichotomous language test data, a…