WINSTEPS Tutorial 2 - Unidimensionality and Local Independence in Rasch measurement - Part 2

Note: Unidimensionality and local independence are also requirements of other similar techniques such as unidimensional IRT modeling. There are quite a few ways to investigate local independence, which have been investigated in IRT research.
For example: Mx2 (and its p), measures of local independence in IRT modelling. OR the Q3 index which is “the Pearson product-moment correlation of a set of residuals from the IRT model” (Chen & Thissen, 1997, p. 280) which is somewhat less sensitive than the Mx2.

Chen, W. H., & Thissen, D. (1997). Local dependence indexes for item pairs using item response theory. Journal of Educational and Behavioral Statistics, 22, 265-289.

Yen, W. M. (1984). Effects of local item dependence on the fit and equating performance of the three-parameter logistic model. Applied Psychological Measurement, 8, 125-145.