ISO 5725-3-2023 PDF

Full title and description

Accuracy (trueness and precision) of measurement methods and results — Part 3: Intermediate precision and alternative designs for collaborative studies. This part discusses experimental designs and practical guidance for determining intermediate precision and related precision components (including reproducibility and repeatability) and provides worked examples and computations for collaborative studies.

Abstract

This document provides (a) a discussion of alternative experimental designs for the determination of trueness and precision measures including reproducibility, repeatability and selected measures of intermediate precision of a standard measurement method, together with guidance on interpretation and application of the resulting estimates, and (b) worked examples including specific designs and computations to support collaborative studies and intermediate-precision assessments.

General information

• Status: Published.
• Publication date: June 2023.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 17.020; 03.120.30.
• Edition / version: Edition 2 (2023).
• Number of pages: 57 pages (ISO paginated edition).

Scope

The standard addresses alternative experimental designs and analysis approaches for estimating intermediate precision and related precision measures for standard measurement methods. It reviews when different designs are necessary or beneficial, explains interpretation and application of estimates (including components such as operator variability and material heterogeneity), and gives worked examples to illustrate computations and practical implementation in collaborative interlaboratory studies.

Key topics and requirements

• Discussion of alternative experimental designs for collaborative studies (balanced and modified layouts).
• Definitions and interpretation of intermediate precision, repeatability and reproducibility measures.
• Guidance on when to use particular designs to improve estimation reliability and reduce required numbers of participating laboratories.
• Methods to estimate additional precision components (e.g., operator variability, in‑house repeatability ranges).
• Consideration of sample/material heterogeneity and its effect on precision estimates (including split‑level designs).
• Worked examples and step‑by‑step computations for specific study designs and analyses.

Typical use and users

Used by method developers, laboratory validation teams, metrologists, statisticians involved in interlaboratory studies, accreditation bodies, standards committees and quality assurance personnel who need to design collaborative studies or interpret precision data for standardized measurement methods.

Related standards

Part of the ISO 5725 series on accuracy (trueness and precision). Closely related parts include ISO 5725-1 (General principles and definitions), ISO 5725-2 (Basic method for determination of repeatability and reproducibility), ISO 5725-4 (Basic methods for determination of trueness), ISO 5725-5 (Alternative methods for determination of precision) and ISO 5725-6 (Use in practice of accuracy values). These parts together provide the conceptual framework, basic methods and practical applications for accuracy and precision assessment of measurement methods.

Keywords

accuracy, trueness, precision, intermediate precision, repeatability, reproducibility, collaborative study, interlaboratory study, experimental design, measurement uncertainty, operator variability, heterogeneity, statistical methods.

FAQ

Q: What is this standard?

A: ISO 5725-3:2023 is the part of the ISO 5725 series that provides guidance on intermediate precision and alternative experimental designs for collaborative (interlaboratory) studies and worked examples to compute precision measures.

Q: What does it cover?

A: It covers alternative study designs and analysis approaches to determine intermediate precision, repeatability and reproducibility for standardized measurement methods, including practical guidance on interpretation, handling material heterogeneity, estimating operator effects and worked examples of computations.

Q: Who typically uses it?

A: Method developers, laboratory validation specialists, statisticians, accreditation assessors, and standards committee members who design or evaluate interlaboratory precision studies and need practical methods and worked examples.

Q: Is it current or superseded?

A: ISO 5725-3:2023 is the current (published) edition and replaces the earlier ISO 5725-3:1994 (and its corrigenda) as the authoritative edition for Part 3 topics.

Q: Is it part of a series?

A: Yes — it is one part of the ISO 5725 series (Parts 1–6) that collectively define principles, basic and alternative methods, trueness determination and practical use of accuracy values for measurement methods.

Q: What are the key keywords?

A: Key keywords include intermediate precision, reproducibility, repeatability, accuracy, trueness, collaborative study, interlaboratory study, experimental design and statistical methods.