scope:

This International Standard 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 Standard provides recommendations on the interpretation of proficiency testing data by participants in such schemes and by accreditation bodies.

The procedures in this Standard can be applied to demonstrate that the measurement results obtained by laboratories, inspection bodies, and individuals meet specified criteria for acceptable performance.

This Standard is applicable to proficiency testing where the results reported are either quantitative measurements or qualitative observations on test items.

NOTE The procedures in this Standard may also be applicable to the assessment of expert opinion where the opinions or judgments are reported in a form which may 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 compared objectively, the provisions of this Standard that relate to nominal (qualitative) properties may apply.