Implements the Interval Consensus Model (ICM) for analyzing continuous bounded interval-valued responses in psychometrics using 'Stan' for 'Bayesian' estimation. Provides functions for transforming interval data to simplex representations, fitting item response theory (IRT) models with isometric log-ratio (ILR) and sum log-ratio (SLR) link functions, and visualizing results. The package enables aggregation and analysis of interval-valued response data commonly found in psychological measurement and related disciplines. Based on Kloft et al. (2024) <doi:10.31234/osf.io/dzvw2>.
| Version: | 0.1.0 | 
| Depends: | R (≥ 4.1) | 
| Imports: | dplyr, ggdist, ggokabeito, ggplot2, methods, posterior, purrr, Rcpp (≥ 0.12.0), RcppParallel (≥ 5.0.1), rstan (≥ 2.18.1), rstantools (≥ 2.4) | 
| LinkingTo: | BH (≥ 1.66.0), Rcpp (≥ 0.12.0), RcppEigen (≥ 0.3.3.3.0), RcppParallel (≥ 5.0.1), rstan (≥ 2.18.1), StanHeaders (≥
2.18.0) | 
| Suggests: | testthat (≥ 3.0.0) | 
| Published: | 2025-07-08 | 
| DOI: | 10.32614/CRAN.package.intervalpsych | 
| Author: | Matthias Kloft  [aut, cre, cph],
  Björn S. Siepe  [aut] | 
| Maintainer: | Matthias Kloft  <kloft.dev+intervalpsych at gmail.com> | 
| BugReports: | https://github.com/matthiaskloft/intervalpsych/issues | 
| License: | GPL (≥ 3) | 
| URL: | https://matthiaskloft.github.io/intervalpsych/,
https://github.com/matthiaskloft/intervalpsych | 
| NeedsCompilation: | yes | 
| SystemRequirements: | GNU make | 
| Materials: | README, NEWS | 
| CRAN checks: | intervalpsych results |