ASTM_D_4270_-_95_2001.pdf

Designation:D 4270 95(Reapproved 2001)Standard Guide forUsing Existing Practices in Developing and Writing TestMethods1This standard is issued under the fixed designation D 4270;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide is intended to assist task groups in thepreparation of a test method.It can help the task group useexisting statistically related ASTM practices more effectivelyduring the development and writing of the test method.1.2 Some of the essential activities that should occur duringthe development of a new test method are not in existing orproposed practices under the jurisdiction of ASTM Subcom-mittee D13.93 on Statistics.This guide includes a briefexplanation of how such activities should be carried out.1.3 This guide is applicable to properties that are evaluatedby both parametric and nonparametric methods of estimation.The instructions on properties that are best evaluated bynonparametric methods are less complete than those forproperties that are evaluated by parametric methods.2.Referenced Documents2.1 ASTM Standards:D 123 Terminology Relating to Textiles2D 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data2D 2905 Practice for Statements on Number of Specimensfor Textiles2D 2906 Practice for Statements on Precision and Bias forTextiles2D 3777 Practice for Writing Specifications for Textiles3D 4271 Practice for Writing Statements on Sampling in TestMethods for Textiles3D 4356 Practice for Establishing Consistent Test MethodTolerances4D 4467 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Non-Normally Distributed Data3D 4853 Guide for Reducing Test Variability3D 4854 Guide for Estimating the Magnitude of Variabilityfrom Expected Sources in Sampling Plans3D 4855 Practice for Comparing Test Methods3E 456 Terminology Relating to Quality and Statistics4E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method42.2 ASTM Adjuncts:5TEX-PACNOTE1TEX-PAC is a group of PC programs on floppy disk.3.Terminology3.1 Definitions:3.1.1 moving range,MR,nthe difference without regardto sign between two successive observations.3.1.2 nonparametric,adjin statistics,a term referring to atechnique that is not based on assumptions about the nature ofthe underlying frequency distribution.(Compare to paramet-ric.)3.1.3 parametric,adjin statistics,a term referring to atechnique that assumes the nature of the underlying distributionis known.(Compare to nonparametric.)3.1.4 practice,na definitive procedure for performing oneor more specific operations or functions that does not producea test result.3.1.4.1 DiscussionA practice is not a down-graded testmethod.Examples of practices include procedures for conduct-ing interlaboratory testing programs or other statistical proce-dures;for writing statements on sampling or precision andaccuracy;and for selection,preparation,application,inspec-tion,necessary precautions for use or disposal,installation,maintenance,and operation of testing equipment.3.1.5 test method,na definitive procedure for the identi-fication,measurement,or evaluation of one or more qualities,characteristics,or properties of a material,product,system,orservice that produces a test result.3.1.6 For the definitions of other terms that appear in thisstandard,refer to Terminology D 123 and Terminology E 456.4.Summary of Guide4.1 The guide is summarized in Fig.1,which shows thesteps in test method development,the sections of this guidewhich apply,and other references that may be used as aids ina specific step in the development of the test method.As Fig.1 points out,the references should show to which of theprevious steps the development should revert when the results1This guide is under the jurisdiction of ASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.93 on Statistics.Current edition approved May 15,1995.Published July 1995.Originallypublished as D 4270 83.Last previous edition D 4270 90.2Annual Book of ASTM Standards,Vol 07.01.3Annual Book of ASTM Standards,Vol 07.02.4Annual Book of ASTM Standards,Vol 14.02.5PC programs on floppy disk are available through ASTM.For a 312in.diskrequest PCN:12-429040;for a 514in.disk request PCN:12-429041-18.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.of a specific step are less than satisfactory.5.Significance and Use5.1 There are enough existing practices related to thedevelopment of test methods or the preparation of one or moresections of new test methods so that even the experiencedauthor may not use them as effectively as possible.This guideshows the person(s)preparing a new test method where andwhen the existing