NF ISO 5725-3, X06-041-3 (08/2023)

This document provides: a) a discussion of alternative experimental designs for the determination of accuracy and precision measures, including reproducibility, repeatability and selected measures of intermediate precision of a standard measurement method, including a review of the circumstances in which their use is necessary or beneficial, together with recommendations regarding the interpretation and application of the resulting estimates; and b) detailed examples, including specific plans and calculations. Each of the alternative plans discussed in this document is intended to address one (or more) of the following issues: a) a discussion of the implications of the definitions of intermediate fidelity measures; (b) recommendations for the interpretation and application of estimates of intermediate precision measures in practical situations; (c) determination of reproducibility, repeatability and selected measures of intermediate precision; (d) improved determination[1] of reproducibility and other measures of precision; e) improving the estimate of the sample mean; f) determination of the range of internal repeatability standard deviations; g) determination of other components of fidelity, such as operator variability; h) determining the level of reliability of precision estimates; (i) reducing the minimum number of participating laboratories by optimizing the reliability of precision estimates; j) avoidance of biased estimates of repeatability (split-level designs); k) avoidance of biased estimates of reproducibility (taking into account material heterogeneity). It often happens that the performance of the method whose precision is subject to evaluation in a collaborative study has already been evaluated as part of an intralaboratory validation study carried out by the laboratory which developed it. Relevant factors for determining intermediate precision have therefore already been identified during this previous intralaboratory study. [1] Authorizing a reduction in the number of laboratories.
(Automatic translation from French)