ASTM_E_1697_-_05_2012e1.pdf

Designation:E169705(Reapproved 2012)1Standard Test Method forUnipolar Magnitude Estimation of Sensory Attributes1This standard is issued under the fixed designation E1697;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.1NOTEEditorially corrected 11.3 and changed“panelist”to“assessor”throughout in August 2012.1.Scope1.1 This test method describes a procedure for the applica-tion of unipolar magnitude estimation to the evaluation of themagnitude of sensory attributes.The test method coversprocedures for the training of assessors to produce magnitudeestimations and statistical evaluation of the estimations.1.2 Magnitude estimation is a psychophysical scaling tech-nique in which assessors assign numeric values to the magni-tude of an attribute.The only constraint placed upon theassessor is that the values assigned should conform to a ratioprinciple.For example,if the attribute seems twice as strong insample B when compared to sample A,sample B shouldreceive a value which is twice the value assigned to sample A.1.3 The intensity of attributes such as pleasantness,sweetness,saltiness or softness can be evaluated using magni-tude estimation.1.4 Magnitude estimation may provide advantages overother scaling methods,particularly when the number of asses-sors and the time available for training are limited.Withapproximately 1 h of training,a panel of 15 to 20 naiveindividuals can produce data of adequate precision and repro-ducibility.Any additional training that may be required toensure that the assessors can properly identify the attributebeing evaluated is beyond the scope of this test method.2.Referenced Documents2.1 ASTM Standards:2E253 Terminology Relating to Sensory Evaluation of Mate-rials and ProductsE1871 Guide for Serving Protocol for Sensory Evaluation ofFoods and Beverages2.2 ASTM Publications:3Manual 26 Sensory Testing Methods,2nd EditionSTP 758Guidelines for the Selection and Training ofSensory Panel Members2.3 ISO Standards:4ISO11056:1999 SensoryAnalysisMethodologyMagnitude Estimation MethodISO 4121:1987SensoryAnalysisMethodologyEvaluation of Food Products by Methods Using ScalesISO/DIS 5492:1990 Sensory AnalysisVocabulary(1)ISO 6658:1985 Sensory AnalysisMethodologyGeneralGuidanceISO/DIS 8586-1:1989 Sensory AnalysisMethodologyGeneral Guide for Selection,Training and MonitoringSubjectsPart 1:Qualifying Subjects(1)ISO 8589:1988 Sensory AnalysisGeneral Guidance forthe Design of Test Rooms3.Terminology3.1 Definitions:3.1.1 external modulusnumber assigned by the panelleader to describe the intensity of the external reference sampleor the first sample of the sample set.The external modulus issometimes referred to as a“fixed modulus”or just the“modulus.”In this case the reference is said to be modulated.3.1.2 external reference sample for magnitude estimationsample designated as the one to which all others are to becompared,or to which the first sample of a set is to becompared,when each subsequent sample in the set is comparedto the preceding sample.This sample is normally the firstsample to be presented.3.1.3 internal modulusnumber assigned by the assessor todescribe the intensity of the external reference sample or thefirst sample of the sample set.The internal modulus issometimes referred to as a“non-fixed modulus.”When aninternal modulus is used,the reference is sometimes said to beunmodulated.1This test method is under the jurisdiction ofASTM Committee E18 on SensoryEvaluation and is the direct responsibility of Subcommittee E18.03 on SensoryTheory and Statistics.Current edition approved Aug.1,2012.Published August 2012.Originallyapproved in 1995.Last previous edition approved in 2005 as E1697 05.DOI:10.1520/E1697-05R12E01.2For 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 ASTM Headquarters,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 1942829593.4Available 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 3.1.4 internal reference sample for magnitude estimationsample present in the experimental set,which is presented tothe assessor as if it were a test sample.The value assigned tothis sample(s)can be used for normalizing assessors data.Ifan external reference is used,the internal reference(s)arenormally identical to it.3.1.5 magnitude estimationprocess of assigning values tothe intensities of an attribute of products in such a way that theratios of the values assigned and the assessors perceptions ofthe attrib