Cohen's κ (agreement)
§7.1
Rev 4.6 · reviewed Feb 2026Cohen's κ — agreement
Measures agreement between two raters beyond chance. Enter the agreement matrix, one row per rater-1 category, columns for rater-2. Diagonal = agreements.
Source formula: Cohen J. Educ Psychol Meas 1960;20:37–46.
| Observed agreement (pₒ) | 84.0% |
| Expected by chance (pₑ) | 50.0% |
| κ | 0.680 |
* Cohen J. Educ Psychol Meas 1960;20:37–46.
† Interpretation bands per Landis JR, Koch GG. Biometrics 1977;33:159–74.
95% CI
0.477 to 0.883
copyStrength of agreement
substantial
copyκ = 0.68 reflects substantial agreement beyond chance. κ can be low even with high raw agreement when one category dominates (the prevalence paradox), so report pₒ alongside it.
Understand what this is measuring