Invited Commentary: Improving Instruments to Counter the Bias in Their Construction

In this issue of the Journal, Villalonga-Olives et al. (Am J Epidemiol. 2023;192(8):1264–1273) examined the psychometric properties of social capital indicators, comparing responses from Black and White people to identify whether there was differential item functioning (DIF) in social capital by race, and also when stratified by educational attainment, as a measure of socioeconomic status. The authors tested whether there is DIF in social capital items between Black and White people and found that DIF across these items was significant although not large, but they were still indicative of measurement error, which they suspected was related to the way these items were developed—that is, based on cultural assumptions tested in mainstream White America. However, some gaps remain to be fleshed out.