Analogous to quantitative test, it is important to understand the imprecision (random variation) associated with a qualitative test. This talk will describe a framework and terminology for how to think about imprecision of a qualitative test and provide suggestions for how to evaluate it. This framework is described in recently published CLSI document EP12-A2 (2008): User Protocol for evaluation of qualitative test performance: Approved guideline, and it is also referenced in Guidance for Industry and FDA Staff: Recommendations for Clinical Laboratory Improvement Amendments of 1988 (CLIA) Waiver Applications for Manufacturers of In Vitro Diagnostic Devices, issued on January 30, 2008.