VEMIRT is created to assist researchers to conduct exploratory and confirmatory multidimensional item response theory (MIRT) analysis and cooresponding item differential functioning (DIF) analysis. The core computation engine of VEMIRT is a family of Gaussian Variational EM algorithms that are considerably more efficient than currently available algorithms in other software packages, especially when the number of latent factors exceeds four.
Identifying the number of factors
pa_poly identifies the number of factors via parallel analysis.
Exploratory factor analysis
E2PL_gvem_rotconducts M2PL Analysis with post-hoc rotation (Promax & CF-Quartimax)E2PL_gvem_lassoconducts M2PL Analysis with Lasso penaltyE2PL_gvem_adaptlassoconducts M2PL Analysis with adaptive Lasso penaltyE2PL_iwconducts importance sampling to correct bias for M2PL analysisE3PL_sgvem_rotconducts stochastic GVEM to further improve the computational effficiency for exploratory M3PL analysisE3PL_sgvem_lassoconducts M3PL Analysis with Lasso penaltyE3PL_sgvem_adaptlassoconducts M3PL Analysis with adaptive Lasso penaltyMGRM_gvemconducts GVEM for the multidimensional graded response model with post-hoc rotationMGPCM_gvemconducts GVEM for the multidimensional partial credit model with post-hoc rotation
Confirmatory factor analysis
C2PL_gvemconducts GVEM for confirmatory M2PL analysisC2PL_bsconducts bootstrap sampling to correct bias and produce standard errors for confirmatory M2PL analysisC2PL_iwconducts importance sampling to correct bias for M2PL analysisC2PL_iw2conducts IW-GVEM for confirmatory M2PL analysis (alternative implementation toC2PL_iw)C3PL_sgvemconducts stochastic GVEM for confirmatory M3PL analysisMGRM_gvemconducts GVEM for the multidimensional graded response modelMGPCM_gvemconducts GVEM for the multidimensional partial credit model
Differential item functioning analysis
D1PL_emconducts DIF analysis for M1PL models using EM algorithmsD1PL_gvemconducts DIF analysis for M1PL models using GVEM algorithmsD2PL_emconducts DIF analysis for M2PL models using EM algorithmsD2PL_pair_emconducts DIF analysis for 2PL models using EM algorithms with group pairwise truncated \(L_1\) penaltyD2PL_gvemconducts DIF analysis for M2PL models using GVEM algorithmsD2PL_lrtconducts DIF analysis for M2PL models using the likelihood ratio test
Shiny apps for VEMIRT
shinyVEMIRTRun the shiny app for VEMIRTDIFdashboardRun the shiny app for DIF Dashboard
Author
Maintainer: Weicong Lyu weiconglyu@um.edu.mo (ORCID)
Authors:
Yijun Cheng chengxb@uw.edu (ORCID)
Jiaying Xiao jxiao6@uw.edu (ORCID)
He Ren heren@uw.edu (ORCID)
Ruoyi Zhu zhux0445@uw.edu (ORCID)
Gongjun Xu gongjun@umich.edu (ORCID)
Chun Wang wang4066@uw.edu (ORCID)