1. Scope

Keywords

Rationale

Many of the test methods in E33 are only performed by a handful of laboratories. Those performing interlaboratory studies to determine precision and bias often need to contend with small numbers of participating laboratories. In addition, the techniques presented in E691 and other related standards assume that each result is completely independent of other results for the same material and that is not strictly true when dealing with results over a range of frequencies. And some of the classification methods used in E33 standards provide a numerical classification that is obtained by a complex curve fitting process. Applying the standard statistical techniques to these classifications, which is often done, may result in misleading precision estimates.