Formulation and Application of the Hierarchical Generalized Random-Situation Random-Weight MIRID.

The process-component approach has become quite popular for examining many psychological concepts. A typical example is the model with internal restrictions on item difficulty (MIRID) described by Butter (1994) and Butter, De Boeck, and Verhelst (1998). This study proposes a hierarchical generalized random-situation random-weight MIRID. The proposed model is more flexible for formulating endogenous latent variables within a multilevel framework, allowing the analysis of polytomous data with complex models (e.g., including item discriminations, random situations, random weights, and heteroskedasticity). The parameters in the proposed model can be estimated using the computer program WinBUGS, which adopts Markov Chain Monte Carlo algorithms. To illustrate the application of the proposed model, a real data set about guilt is analyzed and a comparison of MIRIDs for various conditions is conducted.