Title: proficiency testing
Long Title: IUPAC Gold Book - proficiency testing
DOI: 10.1351/goldbook.08101
Status: current

Definition
Evaluation of the performance of a participant in an interlaboratory comparison against pre-established criteria.

Notes
1) Proficiency testing is achieved by the distribution of proficiency test items for unsupervised measurement or examination by the participants.
2) Participation in proficiency testing schemes is not a substitute for internal quality control measures or vice versa.
3) The evaluation of quantitative results of a participant in a proficiency testing scheme may be given as a \(z\) score, \(z'\) score, \(\zeta\) score, or \(E_{\rm{n}}\) score (see performance score).
4) The term "proficiency testing" includes, but is not limited to, a) quantitative scheme—where the objective is to quantify one or more measurands of the proficiency test item; b) qualitative scheme—where the objective is to identify or describe one or more characteristics of the proficiency test item; c) sequential scheme—where one or more proficiency test items are distributed sequentially for testing or measurement and results returned to the proficiency testing provider at intervals; d) simultaneous scheme—where proficiency test items are distributed for concurrent testing or measurement within a defined time period; e) single occasion exercise—where proficiency test items are provided on a single occasion; f) continuous scheme—where proficiency test items are provided at regular intervals; g) sampling—where samples are taken for subsequent chemical analysis; and h) data transformation and interpretation—where sets of data or other information are furnished
						and the information is processed to provide an interpretation (or other outcome).
5) Some proficiency testing providers in the laboratory medicine area use the term "external quality assessment (EQA)" for their proficiency testing schemes or for their broader programmes, or both.

Related Terms
- chemical analysis: https://goldbook.iupac.org//terms/view/08004
- internal quality control: https://goldbook.iupac.org//terms/view/08082
- participant in an interlaboratory comparison: https://goldbook.iupac.org//terms/view/08093
- performance score: https://goldbook.iupac.org//terms/view/08095
- proficiency test items: https://goldbook.iupac.org//terms/view/08100
- proficiency testing provider: https://goldbook.iupac.org//terms/view/08102
- proficiency testing schemes: https://goldbook.iupac.org//terms/view/08104
- sampling: https://goldbook.iupac.org//terms/view/08043
- testing: https://goldbook.iupac.org//terms/view/08049

Source
- PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1033 (https://doi.org/10.1515/pac-2019-0819)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08101/html
- json: https://goldbook.iupac.org/terms/view/08101/json
- xml: https://goldbook.iupac.org/terms/view/08101/xml

Citation: Citation: 'proficiency testing' 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.08101
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: 2026-07-24T03:31:00+00:00