Changelog • easyRaschBayes

easyRaschBayes 0.3.0 (development)

New custom brms family hurdle_acat for hurdle partial credit models (H-PCM). This is written by Kristoffer Magnusson
Several adapted (experimental) functions for H-PCM, all using the *_hpcm suffix.
- infit_statistic_hpcm()
- q3_statistic_hpcm()
- item_parameters_hpcm()
- person_parameters_hpcm()
- RMUreliability_hpcm()
- plot_icc_hpcm()
- plot_targeting_hpcm()
Bug fix(ish) - changed post processing functions to use median_hdci() instead of median_hdi() to avoid issues with multimodal posteriors.

CRAN release: 2026-04-23

CRAN release: 2026-03-28

Updates:
- infit_statistic() is now faster and defaults to not output outfit statistics, since these are of dubious value (see Müller 2020 and Johansson, 2025).
- item_restscore_statistic() is now faster and has output similar to infit_post().
- q3_statistic() is now faster and has output similar to infit_post().
- plot_residual_pca() is now faster.
Three post-processing helper functions that output a list with result table(s) and a plot:
- infit_post() for the output of infit_statistic()
- item_restscore_post() for the output of item_restscore_statistic()
- q3_post() for the output of q3_statistic()
Other new functions:
- plot_icc() can both produce a basic conditional Item Characteristic Curves plot and optionally a DIF ICC plot, the latter also reporting a partial gamma DIF magnitude coefficient. This is inspired by iarm::ICCplot()
- item_parameters() to retrieve item threshold locations
- person_parameters() to retrieve person locations (latent scores) using EAP and WLE, and also a transformation table from ordinal sum score to EAP/WLE.
- posterior_to_prior() that extracts priors from a brmsfit model that may be useful in model fit assessment. An article will be added later, exploring this further.
- plot_tile(), plot_bars(), and plot_stackedbars() uses wide format item data to create plots to review response patterns.

CRAN release: 2026-03-11