Repeatability

Precision in repeated analytical results

Repeatability is defined in ICH Q2(R2) Validation of Analytical Procedures as "Precision under the same operating conditions over a short interval of time. Repeatability is also termed intra-assay precision." Reapeatability measures the closeness of a measured value during a single study performed by a single analyst on a piece of equipment to assess how close each measured value is too each other. For analytical method validation reapeatability must be assessed with either 6 determinations at 100% of the specifications or 3 replicates at 3 different concentrations for a total of 9 determinations.