ABSTRACT
Interlaboratory comparisons — organization, performance, and evaluation of tests on the same or similar test items by two or more laboratories in accordance with predetermined conditions. Proficiency testing — determination of laboratory testing performance by means of interlaboratory comparisons. Certification study — a study that assigns a reference value to a given parameter (e.g., analyte concentration) in a tested material or a given sample, usually with a determined uncertainty. Method performance study — interlaboratory research in which all participants act according to the same protocol and use the same test procedures to determine the characteristic features in a batch of identical test samples.
