The Joint Committee for Guides in Metrology (JCGM) has prepared this document to promote the sound
evaluation of measurement uncertainty through the use of the GUM (see clause 2) and to provide an introduc-
tion to the GUM Supplements and other documents JCGM is producing: JCGM 101:2008 (see clause 2) and
references [3, 4, 5, 6, 7].
As in the GUM, this document is primarily concerned with the expression of uncertainty relating to the mea-
surement of a well-dened quantity|the measurand [JCGM 200:2008 (VIM) 2.3]|that can be characterized
by an essentially unique true value [JCGM 200:2008 (VIM) 2.11 NOTE 3]. The GUM provides a rationale for
not using the term `true', but this term will be kept in this document when there is otherwise a possibility for
ambiguity or confusion.
The purpose of the GUM Supplements and the other documents produced by the JCGM is to help with the
interpretation of the GUM and enhance its application. The GUM Supplements and the other documents are
together intended to have a scope that is considerably broader than that of the GUM.
This document introduces measurement uncertainty, the GUM, and the GUM Supplements and other documents
that support the GUM. It is directed predominantly at the measurement of quantities that can be characterized
by continuous variables such as length, temperature, time, and amount of substance.
This introductory document is aimed at the following, including but not limited to
| scientic activities and disciplines in general,
| industrial activities and disciplines in general,
| calibration, testing and inspection laboratories in industry, and laboratories such as those concerned with
health, safety and environment, and
| evaluation and accreditation bodies.
It is hoped that it will also be useful to designers, because a product specication that takes better account of
inspection requirements (and the associated measurement) can result in less stringent manufacturing require-
ments. It is also directed at academia, with the hope that more university departments will include modules on
measurement uncertainty evaluation in their courses. As a result, a new generation of students would be better
armed to understand and provide uncertainty statements associated with measured quantity values, and thus
gain an improved appreciation of measurement.
This introductory document, the GUM, the GUM Supplements and the other documents should be used in con-
junction with the `International Vocabulary of Metrology|Basic and general concepts and associated terms'
and all three parts of ISO 3534 cited in clause 2, which dene statistical terms (used in statistics and proba-
bility, including applied statistics and design of experiments), and express them in a conceptual framework in
accordance with normative terminology practice. The last consideration relates to the fact that the theoretical
background of evaluation of measurement data and evaluation of the uncertainty of measurement is supported
by mathematical statistics and probability.
ISO/IEC GUIDE 98-1:2009 Referenced Document
ISO 3534-1:2006 Statistics - Vocabulary and symbols - Part 1: General statistical terms and terms used in probability
ISO 3534-2:2006 Statistics - Vocabulary and symbols - Part 2: Applied statistics
ISO 3534-3:1999 Statistics - Vocabulary and symbols - Part 3: Design of experiments
ISO/IEC GUIDE 98-1:2009 history
2024ISO/IEC Guide 98-1:2024 Guide to the expression of uncertainty in measurement — Part 1: Introduction
2009ISO/IEC GUIDE 98-1:2009 Uncertainty of measurement — Part 1: Introduction to the expression of uncertainty in measurement