Interactive and Step by Step Analyses of Test and Item Properties with difNLR and ShinyItemAnalysis
This talk introduces two R packages used for step by step instruction on psychometric models: Package ShinyItemAnalysis is used for interactive analysis of test and item properties with R. Starting with traditional methods, it moves through regression models with different parametrizations to IRT models. Methods for detection of differential item functioning (DIF) are then presented as further extension of these models. Part of DIF detection methods - those based on generalizations of logistic regression models - are provided by package difNLR, also presented in this talk.