Chance-corrected Agreement Coefficients

The irrCAC is an Python package that provides several functions for calculating various chance-corrected agreement coefficients. This package closely follows the general framework of inter-rater reliability assessment presented by Gwet (2014).

The functionality covers calculations for various chance-corrected agreement coefficients (CAC) among 2 or more raters. Among the CAC coefficients covered are Cohen’s kappa, Conger’s kappa, Fleiss’ kappa, Brennan-Prediger coefficient, Gwet’s AC1/AC2 coefficients, and Krippendorff’s alpha. Multiple sets of weights are proposed for computing weighted analyses.

The functions included in this package can handle 2 types of input data. Those types with the corresponding coefficients are in the following lists:

  1. Contingency Table:

  1. Brennar-Prediger

  2. Cohen’s kappa

  3. Gwet AC1/AC2

  4. Krippendorff’s Alpha

  5. Percent Agreement

  6. Schott’s Pi

  1. Raw Data:

  1. Conger’s kappa

  2. Brennar-Prediger

  3. Gwet AC1/AC2

  4. Fleiss’ kappa

  5. Krippendorff’s Alpha

The package also supports functionality for weighted analysis using a set of predefined weights and interpreting the level of agreement using benchmarking.

Please refer to usage and the api for more.

Note

All of these statistical procedures are described in details in

Gwet, K.L. (2014,ISBN:978-0970806284): “Handbook of Inter-Rater Reliability,” 4th edition, Advanced Analytics, LLC.

This package is a port (with permission) to Python of the irrCAC library for R by Gwet, K.L.

Important

This is a work in progress and does not have (yet) the full functionality found in the R library.

Indices and tables