The Performance of Local Dependence Measures With Psychological Data

The violation of the assumption of local independence when applying item response theory (IRT) models has been shown to have a negative impact on all estimates obtained from the given model. Numerous indices and statistics have been proposed to aid analysts in the detection of local dependence (LD). A Monte Carlo study was conducted to evaluate the relative performance of selected LD measures in conditions considered typical of studies collecting psychological assessment data. Both the Jackknife Slope Index and likelihood ratio statistic G2 are available across the two IRT models used and displayed adequate to good performance in most simulation conditions. The use of these indices together is the final recommendation for applied analysts. Future research areas are discussed.