D3mirt - Descriptive 3D Multidimensional Item Response Theory Modeling

For identifying, estimating, and plotting descriptive multidimensional item response theory models, restricted to 3D and dichotomous or polytomous data that fit the two-parameter logistic model or the graded response model. The method is primarily exploratory and centered on the plot function, which exposes item characteristics and constructs, represented by vector arrows, within a three-dimensional interactive latent space. The results can be useful for item-level analysis as well as test development.