Changes in version 1.0.1 (2025-10-06)                  

  - mix_mod() added: fits a mixed model considering multiple covariates.
  - Power calculation and power curve functions added for statistical
    analysis and visualization.
  - Backtick issues in sample_size_planning outputs fixed for improved
    readability.
  - Function arguments and return values harmonized across the package
    for consistency and ease of use.

                 Changes in version 0.2.1 (2024-09-16)                  

  - minor bug fixes

                 Changes in version 0.2.0 (2023-05-02)                  

  - function "Testing item discriminations" added
  - invar_test() function update: RS test statistic computable, in case
    Group 1 and/or 2 model not identified from the data.
  - minor bug fixes

                 Changes in version 0.1.1 (2021-05-04)                  

  - functions for power and sample size computations are added
  - minor bug fixes

                 Changes in version 0.1.0 (2019-09-20)                  

First CRAN release.