why is the item response theory model poor fitting? what is a poor fit for an item response model? what are latent variables which is best latent variable fit which factor is the chi squared residual of the latent variable? how to model a multiple choice r test how to fit items in item response theory what is the cutoff for item response how to calculate latent variable scores using the ltm package what kind chi squared residuals are required to fit an r model how to fit ltm to a test score what model does ltm use how to fit the items in the r test how to measure fit for item response theory which latent variable is most important in a class quiz? how to use item response theory model what is the latent variable for r average latent variable score chi squared how do you calculate the latent variable on a r test score how can i use item response theory to fit multiple choice quizzes?