Methoden vergleichen

	Gwet's AC1	Fleiss' Kappa für die Übereinstimmung mehrerer Beurteiler
Fachgebiet	Communication	Statistik
Familie	Process / pipeline	Hypothesis test
Entstehungsjahr	2008	1971
Urheber	Kilem L. Gwet	Joseph L. Fleiss
Typ	Chance-corrected agreement coefficient robust to the prevalence paradox	Non-parametric agreement measure
Wegweisende Quelle	Gwet, K. L. (2008). Computing inter-rater reliability and its variance in the presence of high agreement. British Journal of Mathematical and Statistical Psychology, 61(1), 29–48.	Fleiss, J.L. (1971). Measuring Nominal Scale Agreement Among Many Raters. Psychological Bulletin, 76(5), 378–382.
Aliasnamen	Gwet AC1, AC1 coefficient, Gwet's first-order agreement coefficient, Gwet AC1 Katsayısı	multi-rater kappa, Fleiss kappa, Fleiss' Kappa (Çoklu Değerlendirici Uyumu)
Verwandt	4	2
Zusammenfassung	Gwet's AC1 is a chance-corrected agreement coefficient introduced by Kilem Gwet in 2008 as a robust alternative to Cohen's and Fleiss' kappa. It targets the kappa paradox — the unsettling result where coders agree on the vast majority of units yet kappa is near zero because one category dominates — by estimating chance agreement in a way that does not collapse when category prevalence is extreme.	Fleiss' Kappa is a non-parametric statistic for measuring the degree of agreement among three or more raters who classify items into mutually exclusive nominal categories. Introduced by Joseph L. Fleiss in 1971 as a generalization of Cohen's Kappa beyond two raters, it corrects observed agreement for the level of agreement expected by chance alone, making it the standard reliability index in medical diagnosis studies, content analysis, and multi-coder research.