Item Response Theory Approach to Ethnocentrism

Summary

This study applied item response theory (IRT) to scrutinise the psychometric properties of the Ethnocentrism Scale with more rigorous methods than had previously been used for any ethnocentrism measure. The authors modelled how individual items function across the latent trait continuum, evaluating each item's difficulty and discrimination to gauge how well the scale distinguishes people at different levels of ethnocentrism. They also tested for differential item functioning, examining whether respondents from different political groups and gender identities answer particular items differently even when their underlying level of ethnocentrism is equivalent. The analyses supported the scale's measurement quality while pinpointing items biased by group membership. The findings offer guidance for refining ethnocentrism measurement and for interpreting group comparisons in political and intergroup research.