On the Modeling of Local Dependence

Violations of the assumption of local independence are a fundamental issue in item response theory as they threaten model validity and bias the parameter estimates. For such a reason, a plethora of tests and approaches has been devised in the last 40 years to detect or to model such violations. Nonetheless, local dependence (LD) remains an open problem, with somewhat blurred boundaries due to the lack of a general framework for dealing with the different notions of dependence that have been suggested in the literature. The present contribution has a two-fold aim: On the one hand, to review and collect some of the approaches available in the literature; on the other hand, by following a unified perspective on assessment models introduced by Noventa et al. (2024, Journal of Mathematical Psychology 122, 102872) to suggest a possible systematization of some existing and some new approaches to LD. As a result, deterministic and probabilistic modeling mechanisms of LD are formalized and discussed.