1.1 This practice covers a procedure for detecting sources of variation in a test method. The procedure should be used during the development of a test method, before the interlaboratory study is executed, such as those in Practices C 670, C 802, and E 691. Interlaboratory studies can be expensive to execute. Resources will probably be more efficiently used if sources of variation in a test method are eliminated prior to performing the interlaboratory study. The procedure also is useful for determining sources of variation in an existing test method that has been found to have poor precision.

1.2 This practice covers, in very general terms, techniques for planning, collecting data, and analyzing results from a few laboratories. provides the details of the procedure with an example and gives the theoretical background.

1.3 The practice does not give information pertinent to estimating within- or between-laboratory precision.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.