Dictionary · Glossary of Terms for Quality Assurance and Good Laboratory Practices

Technical operation to determine one or more characteristics of or to evaluate the performance of a given product, material, equipment, organism, physical phenomenon, process or service according to a specified procedure.

Ability to trace the history, application or location of an entity by means of recorded identification. ["Chain of custody" is a related term.] Alternatively, traceability is a property of the result of a measurement or the value of a standard whereby it can be related with a stated uncertainty, to stated references, usually national or international standards, i.e. through an unbroken chain of comparisons. In this context, The standards referred to here are measurement standards rather than written standards.

Independent review conducted to compare the various aspects of the laboratory’s performance with a standard for that performance. Also defined as a systematic, independent and documented process for obtaining audit evidence and evaluating it objectively to determine the extent to which audit criteria are fulfilled.

Set of operations that establish, under specified conditions, the relationship between values indicated by a measuring instrument or measuring system, or values represented by a material measure, and the corresponding known values of a measurand.

Confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled.

Closeness of agreement between independent test results obtained under prescribed conditions. It is generally dependent on analyte concentration, and this dependence should be determined and documented. The measure of precision is usually expressed in terms of imprecision and computed as a standard deviation of the test results. Higher imprecision is reflected by a larger standard deviation. Independent test results means results obtained in a manner not influenced by any previous results on the same or similar material. Precision covers repeatability and reproducibility [19]. Alternatively, precision is a measure for the reproducibility of measurements within a set, that is, of the scatter or dispersion of a set about its central value. Precision depends only on the distribution of random errors and does not relate to the true value or specified value.