ASTM_E_2263_-_12.pdf

Designation:E226312Standard Test Method forPaired Preference Test1This standard is issued under the fixed designation E2263;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This document covers a procedure for determiningpreference between two products using either a two-alternativeforced-choice task,or with the option of choosing no prefer-ence.Preference testing is a type of hedonic testing.1.2 A paired preference test determines whether there is astatistically significant preference between two products for agiven population of respondents.The target population must becarefully considered.1.3 This method establishes preference in a single evalua-tion context.Replicated tests will not be covered within thescope of this document.1.4 Paired preference testing can address overall preferenceor preference for a specified sensory attribute.1.5 The method does not directly determine the magnitudeof preference.1.6 This method does not address whether or not twosamples are perceived as different.Refer to Test Method E2164for directional difference test.1.7 Apaired preference test is a simple task for respondents,and can be used with populations that have minimal reading orcomprehension skills,or both.1.8 Preference is not an intrinsic attribute of the product,such as hue is,but is a subjective measure relating torespondents affective or hedonic response.It differs frompaired comparison testing which measures objective character-istics of the product.Preference results are always dependenton the population sampled.1.9 This standard does not purport to address all of thesafety problems associated with its use,when testing includeshazardous materials,operations,or equipment.It is the re-sponsibility of the user of this standard to establish appropriatesafety and health practices and to determine the applicabilityof regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E253 Terminology Relating to Sensory Evaluation of Mate-rials and ProductsE456 Terminology Relating to Quality and StatisticsE1871 Guide for Serving Protocol for Sensory Evaluation ofFoods and BeveragesE1958 Guide for Sensory Claim SubstantiationE2164 Test Method for Directional Difference Test2.2 ISO Standard:ISO 5495 Sensory AnalysisMethodologyPaired Com-parison33.Terminology3.1 For definition of terms relating to sensory analysis,seeTerminology E253,and for terms relating to statistics,seeTerminology E456.3.2 Definitions of Terms Specific to This Standard:3.2.1 (alpha)riskthe probability of concluding that apreference exists when,in reality,one does not.(Also knownas Type I Error or significance level.)3.2.2 (beta)riskthe probability of concluding that nopreference exists when,in reality,one does.(Also known asType II Error.)3.2.3 common responsesfor a one-sided test,the numberof respondents selecting the product that is expected to bepreferred.For a two-sided test,the largest number of respon-dents selecting either product.3.2.4 one-sided testa test in which the researcher has an apriori assumption concerning the direction of the preference.In this case,the alternative hypothesis will express that aspecific product is preferred over another product(that is only,A B or A B),depending on the a priori belief.3.2.5 two-sided testa test in which the researcher does nothave any a priori assumption concerning direction of the1This test method is under the jurisdiction ofASTM Committee E18 on SensoryEvaluation and is the direct responsibility of Subcommittee E18.04 on Fundamen-tals of Sensory.Current edition approved Oct.15,2012.Published December 2012.Originallyapproved in 2004.Last previous edition approved in 2004 as E2263 04.DOI:10.1520/E2263-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 preference.In this case,the alternative hypothesis is that thetwo products are not equally preferred(that is,A B).3.2.6 Pmax a test sensitivity parameter established prior totesting and used along with the selected values of and todetermine the number of respondents needed in a study.Pmaxisthe proportion of common responses that the researcher wantsthe test to be able to detect with a probability of 1-.Forexample,if a researcher wants to have a 90%confidence levelof detecting a 60:40 split in preference,then Pmax=60%and=0.10.3.2.7 sensitivitya general term used to summarize theperformance characterist