Overview | Model Families | Model and Backend Coverage | Estimation Backends | Installation | Quick Start: Traditional IRT | Simulating and Fitting a MIRT Model | Goodness-of-Fit Evaluation | Forced-Choice Modeling | Simulating and Fitting FCMIRT | Thurstonian IRT (TIRT) | Forced-Choice DCM (FCDCM) | Forced-Choice GDINA (FCGDINA) | Working with Polytomous Data | MGPCM (Dominance) | MGGUM (Ideal-Point / Unfolding) | Solution Rotation | Diagnostic Plots | Estimation Control | Common Parameters (top-level) | Stan-Specific Control | iStEM-Specific Control (advanced) | References

Overview | Traditional (Single-Stimulus) Models | MIRT: Multidimensional Item Response Theory | MGPCM: Multidimensional Generalized Partial Credit Model | MGGUM: Multidimensional Generalized Graded Unfolding Model | Forced-Choice (Comparative) Models | FCMIRT: Forced-Choice MIRT | FCGGUM: Forced-Choice GGUM | TIRT: Thurstonian IRT for Forced-Choice | FCDCM: Forced-Choice Diagnostic Classification Model | FCGDINA: Forced-Choice GDINA | Model Selection Guide | Estimation Method Selection | Goodness-of-Fit Framework | References