ISO INTERNATIONAL STANDARD 5495 Third edition 2005-11-15 Sensory analysis Methodology Paired comparison test Analyse sensorielle — Methodologie Essai de comparaison par paires Reference number ISO 5495:2005(E) @ ISO 2005 ISO 5495:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF fle can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ?ISO2005 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, IsO's member body in the country of the requester. ISO copyright office Case postale 56. CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ ISO 2005 - All rights reserved ISO 5495:2005(E) Contents Page Foreword. 1 Scope 2 Normative references 3 Terms and definitions.. 3 4 5 General test conditions. 6 Assessors. 6.1 Qualification .. 6.2 Number of assessors 7 Procedure.. 8 Analysis and interpretation of results 8.1 When testing for a difference 6 8.2 When testing for similarity 9 Report 10 Precision and bias. AnnexA(normative)Tables 8 AnnexB(informative)Examples Bibliography @ iso 2005'- All rights reserved ii ISO5495:2005(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO member bodies). The work of preparing International Standards is normally carried out through IsO non-governmental,inliaisonwithIsO,also take partin the work.Iso collaborates closely withthe International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 adopted by the technical committees are circulated to the member bodies for voting. Publication as an rights: IsO shall not be held responsible for identifying any or all such patent rights. ISO 5495 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 12, Sensory analysis. This third edition cancels and replaces the second edition (IsO 5495:1983), which has been technically revised. @ ISO 2005 - All rights reserved INTERNATIONALSTANDARD ISO5495:2005(E) Sensory analysis Methodology Paired comparison test Scope difference or a similarity between samples of two products concerning the intensity of a sensory attribute. This test is sometimes also referred to as a directional difference test or a 2-AFC test (Alternative Forced Choice). In fact, the paired comparison test is a forced choice test between two alternatives. NOTE The paired comparison test is the simplest existing classification test since it concerns only two samples. The method is applicable whether a difference exists in a single sensory attribute or in several, which means The absence of difference for the attribute under study does not signify that there does not exist any difference between the two products. This method is only applicable if the products are relatively homogeneous. The method is effective a) for determining whether a perceptible difference exists (paired difference test), or whether no perceptible difference exists (paired similarity test) when, for example, modifications are b) for selecting, training and monitoring assessors. It is necessary to know, prior to carrying out the test,