ASTM G117-02(2007)

This guide is intended to assist in developing statements of precision and supporting data that will be used in Committee G02 standards. The methods and approach are drawn from Practice E 177 and E 691. It was felt that preparation of this guide and its use in Committee G02 would lead to appropriate statistical analyses and more uniformity in G02 standards regarding reporting of interlaboratory results and precision. The guide is not meant to substitute for possible use of Practices E 177 or E 691 in developing committee standards.

1.1 This guide covers and offers direction on the handling of data from interlaboratory tests for wear or erosion. It describes a format for entering data and for subsequently reporting results on measures of precision in a Committee G02 standard. It indicates methods for calculation of the needed statistical quantities.

1.2 This guide offers guidance based on a Committee G02 consensus, and exists for the purpose of emphasizing the need to use established statistical practices, and to introduce more uniformity in reporting interlaboratory test results in Committee G02 standards.

1.3 An example of how the methods described in this guide may be applied is available in personal computer format (DOS type system) on floppy disk as a spreadsheet (LOTUS, rel. 4) file. The purpose is to facilitate use of the methods in this guide. The example file contains all needed equations in the recommended format and can be edited to accept new data. ASTM Headquarters or the Chairman of G02 should be contacted for a copy of that computer file. The user must have spreadsheet software (for example, LOTUS or compatible) available.

1.4 The methods used in this document are consistent with Practices E 691 and E 177, and with ADJE0691, Conducting an Interlaboratory Study to Determine the Precision of a Test Method.