ASTM_D_2904_-_97_2002.pdf

Designation:D 2904 97(Reapproved 2002)Standard Practice forInterlaboratory Testing of a Textile Test Method thatProduces Normally Distributed Data1This standard is issued under the fixed designation D 2904;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 practice serves as a guide for planning interlabo-ratory tests in preparation for the calculation of the number oftests to determine the average quality of a textile material asdiscussed in Practice D 2905 and for the development ofstatements on precision as required in Practice D 2906.1.2 The planning of interlaboratory tests requires a generalknowledge of statistical principles including the use of vari-ance components estimated from an analysis of variance.Interlaboratory tests should be planned,conducted,and ana-lyzed after consultation with statisticians who are experiencedin the design and analysis of experiments and who have someknowledge of the nature of the variability likely to be encoun-tered in the test method.1.3 The instructions in this practice are specifically appli-cable to design and analysis of:1.3.1 Single laboratory preliminary trial,1.3.2 Pilot-scale interlaboratory tests,and1.3.3 Full-scale interlaboratory tests.1.4 Guides for decisions pertaining to data transformationsprior to analysis,the handling of missing data,and handling ofoutlying observations are provided.1.5 Procedures given in this practice are applicable to testmethods based on the measurement of continuous variatesfrom normal distributions or from distributions which can bemade normal by a transformation.Get qualified statistical helpto(1)decide if the data are from another known distribution,such as the Poisson distribution,(2)make a judgment onnormality,(3)transform data to a more nearly normaldistribution,or(4)use Practice D 4467.Use the procedures inPractice D 4467 for test methods that produce data that are(1)continuous data that are not normally distributed or(2)discretedata,such as ratings on an arbitrary scale,counts that may bemodelled by use of the Poisson distribution,or proportions orcounts of successes in a specified number of trials that may bemodelled by the binomial distribution.NOTE1Additional information on interlaboratory testing and onstatistical treatment of data can be found in Practice D 1749,D 3040,E 173,E 177,E 691,and Terminology E 456.2.Referenced Documents2.1 ASTM Standards:D 123 Terminology Relating to Textiles2D 1749 Practice for Interlaboratory Evaluation of TestMethods Used with Paper and Paper Products3D 2905 Practice for Statements on Number of Specimensfor Textiles2D 2906 Practice for Statements on Precision and Bias forTextiles2D 3025 Practice for Standardizing Cotton Fiber Test Resultsby Use of Calibration Cotton Standards2D 3040 Practice for Preparing Statements for StandardsRelated to Rubber and Rubber Testing4D 4270 Guide for Using Existing Practices in Developingand Writing Test Methods5D 4467 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Non-Normally Distributed Data5D 4853 Guide for Reducing Test Variability5,6E 173 Practices for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals7E 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods8E 178 Practice for Dealing with Outlying Observations8E 456 Terminology Relating to Quality and Statistics8E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method82.2 ASTM Adjuncts:TEX-PAC9NOTE2Tex-Pac is a group of PC programs on floppy disks,availablethrough ASTM Headquarters,100 Barr Harbor Drive,West Consho-hocken,PA19428,USA.The calculations required by theAnnexes of thispractice can be performed using this adjunct and the ouput is printed in aformat suitable for direct insertion in the Research Report required when1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.93 on Statistics.Current edition approved Nov.10,1997.Published August 1998.Originallypublished as D 2904 73 T.Last previous edition D 2904 91.2Annual Book of ASTM Standards,Vol 07.01.3Annual Book of ASTM Standards,Vol 15.09.4Discontinued.See 1988 Annual Book of ASTM Standards,Vol 09.01.5Annual Book of ASTM Standards,Vol 07.02.6Discontinued.See 1993 Annual Book of ASTM Standards,Vol 07.02.7Annual Book of ASTM Standards,Vol 03.05.8Annual Book of ASTM Standards,Vol 14.02.9PC programs on floppy disks are available throughASTM.RequestADJD2904.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.an interlaboratory evaluation is conducted for the purpose of establishingthe precision of a Test Method.3.Terminology3.1 For definitions of text