Multi-rater delta: extending the delta nominal measure of agreement between two raters to many raters Martín Andrés, Antonio Álvarez Hernández, María Cohen's kappa Conger's kappa Delta agreement Fleiss’ kappa Hubert's kappa Nominal agreement This research was supported by the Spanish Ministry of the Economy, Industry and Competitiveness under grant number MTM2016-76938-P (co-financed by funding from FEDER). The authors declare that there is no conflict of interest. The authors wish to thank Dr. Pedro Femia Marzo for his invaluable assistance in various aspects of this article. The need to measure the degree of agreement among R raters who independently classify n subjects within K nominal categories is frequent in many scientific areas. The most popular measures are Cohen's kappa (R = 2), Fleiss' kappa, Conger's kappa and Hubert's kappa (R $\geq$ 2) coefficients, which have several defects. In 2004, the delta coefficient was defined for the case of R = 2, which did not have the defects of Cohen's kappa coefficient. This article extends the coefficient delta from R = 2 raters to R $\geq$ 2. The coefficient multi-rater delta has the same advantages as the coefficient delta with regard to the type kappa coefficients: i) it is intuitive and easy to interpret, because it refers to the proportion of replies that are concordant and non random; ii) the summands which give its value allow the degree of agreement in each category to be measured accurately, with no need to be collapsed; and iii) it is not affected by the marginal imbalance. 2022-01-19T12:14:20Z 2022-01-19T12:14:20Z 2019 journal article Publisher version: A. Martín Andrés & M. Álvarez Hernández (2021) Multi-rater delta: extending the delta nominal measure of agreement between two raters to many raters, Journal of Statistical Computation and Simulation, [DOI: 10.1080/00949655.2021.2013485] http://hdl.handle.net/10481/72384 10.1080/00949655.2021.2013485 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Taylor and Francis