Pharmaceutical Statistics Using SAS

4.5. Accuracy and Precision

4.5.1. Accuracy (Trueness)

The accuracy (the preferred term is trueness), of an analytical procedure, according to ICH and related documents, expresses the closeness of agreement between the mean value obtained from a series of measurements and the value which is accepted either as a conventional true value or an accepted reference value (e.g., international standard, standard from a pharmacopoeia). It is a measure of the systematic error of test results obtained by the analytical method from its theoretical true/reference value. The measure of trueness is generally expressed in terms of recovery and absolute/relative bias.

Note that "accuracy" is synonymous with bias or trueness only within the pharmaceutical set ...