ASTM G117-13

4.1 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 E177 and E691. 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 E177 or E691 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 as a spreadsheet 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. Contact ASTM Headquarters or the Chairman of G02 for a copy of that computer file. The user must have spreadsheet software (EXCEL or compatible) available.

1.4 The methods used in this document are consistent with Practices E691 and E177.