Classification in which membership of an object in each possible class is given a weight between zero and one.
Note: In so-called hard cluster algorithms membership of a group can only take values 0 or 1, but in fuzzy clustering any value between 0 and 1 is allowed subject to the sum of all memberships of an object being 1.
Source:
PAC, 2016, 88, 407. 'Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)' on page 429 (https://doi.org/10.1515/pac-2015-0605)