EVS-ISO 13528:2023

This document provides detailed descriptions of statistical methods for proficiency testing providers
to use to design proficiency testing schemes and to analyse the data obtained from those schemes. This
document provides recommendations on the interpretation of proficiency testing data by participants
in such proficiency testing schemes and by accreditation bodies.
The procedures in this document can be applied to demonstrate that the measurement results obtained
by laboratories, inspection bodies, and individuals meet specified criteria for acceptable performance.
This document is applicable to proficiency testing where the results reported are either quantitative
measurements or qualitative observations on test items.
NOTE The procedures in this document can also be applied for the assessment of expert opinion where the
opinions or judgments are reported in a form which can be compared objectively with an independent reference
value or a consensus statistic. For example, when classifying proficiency test items into known categories by
inspection - or in determining by inspection whether proficiency test items arise, or do not arise, from the same
original source - and the classification results are comp