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