Roldán López de Hierro, Antonio FranciscoRoldán, ConcepciónGuerra Errea, CarlosFernández Fernández, Francisco JavierCruz, AndersonMoraes, Ronei Marcos deBustince Sola, Humberto2025-02-262025-02-01Roldán López de Hierro, A. F., Roldán, C., Guerra, C., Fernández, J., Cruz, A., Marcos de Moraes, R., Bustince, H. (2025) From type-(2,k) grouping indices to type-(2,k) Jaccard indices. Fuzzy Sets and Systems, 501, 1-22. https://doi.org/10.1016/j.fss.2024.109216.0165-011410.1016/j.fss.2024.109216https://academica-e.unavarra.es/handle/2454/53586In this work, we introduce the notion of grouping index for type-2 fuzzy sets as a measure of how far the union of two type-2 fuzzy sets over the same universe is from the total universe. We also show how we can extend the notion of the Jaccard index to the type-2 setting by means of type-2 grouping and overlap indexes.application/pdfeng© 2024 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0.Fuzzy setType-2 fuzzy setGrouping indexOverlap indexJaccard indexinfo:eu-repo/semantics/article2025-02-26info:eu-repo/semantics/embargoedAccess