Historical
ASTM E691-13
Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
1.1 This practice describes the techniques for planning, conducting, analyzing, and treating the results of an interlaboratory study (ILS) of a test method. The statistical techniques described in this practice provide adequate information for formulating the precision statement of a test method.
1.2 This practice does not concern itself with the development of test methods but rather with gathering the information needed for a test method precision statement after the development stage has been successfully completed. The data obtained in the interlaboratory study may indicate, however, that further effort is needed to improve the test method.
1.3 Since the primary purpose of this practice is the development of the information needed for a precision statement, the experimental design in this practice may not be optimum for evaluating materials, apparatus, or individual laboratories.
1.4 Field of Application—This practice is concerned exclusively with test methods which yield a single numerical figure as the test result, although the single figure may be the outcome of a calculation from a set of measurements.
1.4.1 This practice does not cover methods in which the measurement is a categorization, such as a go-no-go allocation (two categories) or a sorting scheme into two or more categories. For practical purposes, the discontinuous nature of measurements of these types may be ignored when a test result is defined as an average of several individual measurements. Then, this practice may be applicable, but caution is required and a statistician should be consulted.
ASTM International [astm]