Designation:E2139−05(Reapproved2011)StandardTestMethodforSame-DifferentTest1ThisstandardisissuedunderthefixeddesignationE2139;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethoddescribesaprocedureforcomparingtwoproducts.1.2ThistestmethoddoesnotdescribetheThurstonianmodelingapproachtothistest.1.3Thistestmethodissometimesreferredtoasthesimple-differencetest.1.4Asame-differenttestdetermineswhethertwoproductsareperceivedtobethesameordifferentoverall.1.5Theprocedureofthetestdescribedinthistestmethodconsistsofpresentingasinglepairofsamplestoeachassessor.Thepresentationofmultiplepairswouldrequiredifferentstatisticaltreatmentanditisoutsideofthescopeofthistestmethod.1.6Thistestmethodisnotattribute-specific,unlikethedirectionaldifferencetest.1.7Thistestmethodisnotintendedtodeterminethemagnitudeofthedifference;however,statisticalmethodsmaybeusedtoestimatethesizeofthedifference.1.8Thistestmethodmaybechosenoverthetriangleorduo-triotestswheresensoryfatigueorcarry-overareaconcern,orwhereasimplertaskisneeded.1.9Thisstandardmayinvolvehazardousmaterials,operations,andequipment.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E253TerminologyRelatingtoSensoryEvaluationofMate-rialsandProductsE456TerminologyRelatingtoQualityandStatisticsE1871GuideforServingProtocolforSensoryEvaluationofFoodsandBeverages2.2ASTMPublications:2Manual26SensoryTestingMethods,2ndEditionSTP758GuidelinesfortheSelectionandTrainingofSen-soryPanelMembersSTP913GuidelinesforPhysicalRequirementsforSensoryEvaluationLaboratories2.3ISOStandard:3ISO5495SensoryAnalysis—...
