Title: unsupervised classification
Long Title: IUPAC Gold Book - unsupervised classification
DOI: 10.1351/goldbook.10146
Status: current

Definition
Classification in which no prior information about membership of groups is known.

Notes
1) The number of groups may be specified.
2) Algorithms for unsupervised classification include k-means cluster analysis, hierarchical cluster analysis.

Related Terms
- hierarchical cluster analysis: https://goldbook.iupac.org//terms/view/10129
- k-means cluster analysis: https://goldbook.iupac.org//terms/view/10130

Source
- PAC, 2016, 88, 407. 'Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)' on page 433 (https://doi.org/10.1515/pac-2015-0605)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/10146/html
- json: https://goldbook.iupac.org/terms/view/10146/json
- xml: https://goldbook.iupac.org/terms/view/10146/xml

Citation: Citation: 'unsupervised classification' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.10146
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-08-06T04:50:21+00:00