To cite package ‘modelfree’ in publications use:

Marin-Franch I, Zychaluk K, Foster D (2025). modelfree: Model-Free Estimation of a Psychometric Function. R package version 1.2.1, https://CRAN.R-project.org/package=modelfree.

Corresponding BibTeX entry:

  @Manual{,
    title = {modelfree: Model-Free Estimation of a Psychometric
      Function},
    author = {Ivan Marin-Franch and Kamila Zychaluk and David H.
      Foster},
    year = {2025},
    note = {R package version 1.2.1},
    url = {https://CRAN.R-project.org/package=modelfree},
  }