1、 ISO 2014 Sensory analysis Methodology General guidance for conducting hedonic tests with consumers in a controlled area Analyse sensorielle Mthodologie Lignes directrices gnrales pour la ralisation dpreuves hdoniques effectues avec des consommateurs dans un espace contrl INTERNATIONAL STANDARD ISO
2、11136 First edition 2014-12-01 Reference number ISO 11136:2014(E) ISO 11136:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, e
3、lectronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 T
4、el. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO 11136:2014(E)Contents Page Foreword v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Preliminary considerations 3 4.1 Study proposal. 3 4.2 Specification of the targe
5、t population . 4 4.3 Further specifications . 4 5 The consumer sample . 5 5.1 General . 5 5.2 Recruiting the consumers 5 5.3 Assembling a consumer sample . 7 5.4 Sample segmentation . 7 6 Size of the consumer sample 8 6.1 Decisions of measurement 8 6.2 Determining the sample size 8 6.3 Working with
6、subgroups 9 6.4 Number of product samples and experimental design 9 6.5 Safety margin in recruitment . 9 7 Test area .10 8 Products 10 8.1 Anonymous presentation of the products 10 8.2 Preparation and presentation of the products .10 9 Procedures .11 9.1 Two groups of hedonic tests 11 9.2 Rating tes
7、ts 12 9.3 Paired comparison tests 12 9.4 Ranking test .13 9.5 Additional questions .14 9.6 Instructions for the consumers .14 10 Organization of test sessions 15 10.1 General 15 10.2 Plans 15 10.3 Number of products evaluated in a single session 16 10.4 Nature of the products evaluated within a sess
8、ion 17 10.5 Time of the session .17 10.6 Repetition of a product within a test 17 10.7 Pre-test 17 11 Analysis of the results 18 11.1 General 18 11.2 Inferential analysis .18 11.3 Ratings (see 9.2) .18 11.4 Paired comparisons (9.3) 18 11.5 Ranking (9.4) .18 ISO 2014 All rights reserved iii ISO 11136
9、:2014(E)12 Study report 19 12.1 General 19 12.2 Products .19 12.3 Test procedure 20 12.4 Consumers .20 12.5 Results .21 12.6 Annexes to the report .21 Annex A (informative) Example of a recruitment questionnaire 22 Annex B (informative) Methods for evaluating the data of segmentation subgroups .26 A
10、nnex C (informative) Plans for assigning products to consumers 28 Annex D (informative) Influenc e of the sample size on the ac cur acy of one mean .29 Annex E (informative) Minimum sample size for tests using rating.30 Annex F (informative) Minimum sample size for tests using ranking 34 Annex G (in
11、formative) Examples of data analysis for ratings 36 Annex H (informative) Examples of data analysis for rankings 41 Bibliography .43 iv ISO 2014 All rights reserved ISO 11136:2014(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bod
12、ies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organization
13、s, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further
14、 maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives)
15、. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Intro
16、duction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to
17、conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 12, Sensory analysis.
18、 ISO 2014 All rights reserved v Sensory analysis Methodology General guidance for conducting hedonic tests with consumers in a controlled area 1 Scope This International Standard describes approaches for measuring, within a controlled area, the degree to which consumers like or relatively like produ
19、cts. It uses tests based on collecting consumers responses to questions, generally on paper or via a keyboard or a touch screen. Tests of a behavioural nature (such as recording quantities consumed ad libitum by the consumers) do not fall within the scope of this International Standard. The hedonic
20、tests dealt with in this International Standard, can be used as a contribution to the following: comparing a product with competitor products; optimizing a product so that it obtains a high hedonic rating or is liked by a large number of consumers; helping to define a range of products to correspond
21、 to a particular consumer target population; helping to define a best-before date; assessing the impact of a product formulation change on the pleasure given by the product; studying the impact of sensory characteristics of a product on degree to which it is liked, independently of the products extr
22、insic characteristics, such as brand, price, or advertising; studying the effect of a commercial or presentation variable, such as packaging. The methods are effective for determining whether or not, a perceptible preference exists (difference in degree of liking), or whether or not, no perceptible
23、preference (paired similarity test) exists. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of
24、the referenced document (including any amendments) applies. ISO 4121, Sensory analysis Guidelines for the use of quantitative response scales ISO 5492, Sensory analysis Vocabulary ISO 5495, Sensory analysis Methodology Paired comparison test ISO 8587, Sensory analysis Methodology Ranking ISO 8589, S
25、ensory analysis General guidance for the design of test rooms ISO 29842, Sensory analysis Methodology Balanced incomplete block designs 3 T erms a nd definiti ons For the purposes of this document, the terms and definitions given in ISO 5492 and the following apply. INTERNATIONAL ST ANDARD ISO 11136
26、:2014(E) ISO 2014 All rights reserved 1 ISO 11136:2014(E) 3.1 access panel sample database of potential respondents who declare that they will cooperate for future data collection if selected SOURCE: ISO 20252 Note 1 to entry: Respondents can be drawn on a more or less regular basis. 3.2 closed-ende
27、d question question requiring respondents to select from a predetermined list of possible answers 3.3 commissioning party person, body, or service who commissions a third party to conduct a study Note 1 to entry: The concept of commissioning party corresponds to that of purchaser or customer in qual
28、ity control. It contrasts with that of the supplier, service provider, or laboratory Note 2 to entry: Usually, the commissioning party and the service provider belong to different enterprises. Where they belong to two departments of the same enterprise, the respective responsibilities of the two dep
29、artments shall be carefully differentiated and explicitly clarified in the study proposal 3.4 consumer respondent person who uses a product Note 1 to entry: For the purposes of this International Standard, the meaning is restricted to a person who is neither an expert, an expert sensory assessor nor
30、 a selected assessor in conformity with ISO 5492. 3.5 consumer sample group of consumers recruited on the basis of criteria specified by the nature of the target population 3.6 controlled area location providing controlled preparation and presentation of the products, comfortable conditions for cons
31、uming the products and for questioning the consumers, and absence of communication (verbal and non-verbal) between the consumers, guaranteeing independent responses 3.7 hedonic perception amount of pleasure given by the sensory properties of a product 3.8 hedonic test test aimed at measuring the ove
32、rall hedonic perception of a product by consumers 3.9 open-ended question question that does not provide ready-made alternatives for respondents but asks them to answer in their own words Note 1 to entry: It can concern each of the products presented to the consumers or only some of them (e.g. when
33、the question asks why a particular product has appealed most, or least, to an consumer).2 ISO 2014 All rights reserved ISO 11136:2014(E) 3.10 position bias bias related to the location of a product in a set of products being evaluated 3.11 product family group of products that can replace one anothe
34、r under normal conditions of consumption Note 1 to entry: Product families may vary according to culture and consumption habits. 3.12 representativenessdegree to which attributes of the sample agree with relevant attributes of the population from which it is drawn 3.13 sequential bias bias related t
35、o the temporal or sequential position of a product in a set of products being evaluated 3.14 session meeting of consumers working simultaneously according to the same protocol during a defined time period Note 1 to entry: A session can be divided into several subsessions separated by a defined rest
36、time. For example, a session lasting 1 h 30 min can be divided into two subsessions with a 10-min break between them. 3.15 target population population whose hedonic response to a product is to be evaluated 4 Preliminary considerations 4.1 Study proposal The study proposal is drawn up by the service
37、-providing laboratory based on the information (especially concerning the objective of the study and target population) given by the commissioning party, as a written document that binds the laboratory and the commissioning party contractually. It includes the following elements: the objective of th
38、e study; the products to be evaluated (and the procedures for their procurement, especially when the laboratory has to procure one or more products); the target population for the study; the size of the consumer sample (sample size) and the way it is to be recruited; any limitations on consumers pri
39、or history of participation in consumer studies; any limitations on other products to be evaluated in the same testing session; the evaluation conditions; the type of interview (self-completion forms or interviewers); the questionnaire; the place of evaluation; ISO 2014 All rights reserved 3 ISO 111
40、36:2014(E) the number of products to be evaluated per session in the proposed study, together with an indication of other products to be evaluated where the session comprises several product families (where these products are not known at the time of drawing up the proposal, the laboratory should be
41、 committed to communicate them as soon as the laboratory knows the nature of the products); the conditions of preparation specific to the products to be evaluated (if they are known at this stage); any instructions specific to the products to be evaluated (if they are known at this stage) together w
42、ith any specific information to be given about the products or the test at the start of the session; the name of the statistical tests to be used for interpreting the results; the type of risks used and their tolerable values; the magnitude of the minimum difference to be detected in a difference of
43、 liking test or of the maximum tolerable difference in a similarity of liking test; any envisaged segmentation of the consumer population, based either on characteristics known before obtaining judgment data or from the responses obtained; the method of examining and summarizing open-ended questions
44、; any recommendations the commissioning party wishes the laboratory to draft on the basis of the results; the dates envisaged for the tests and for submission of the report. When any of the above elements are unknown at the time of the study proposal, the proposal includes for each element concerned
45、 the following statement: “This element will be specified by the commissioning party by. specifying the stage of the study.” NOTE If a specification already exists, the study proposal may make reference to it without repeating technical points described in an operational manner in the specification.
46、 4.2 Specification of the tar get population In order to specify the target population, it is necessary to answer the following questions. These questions shall be considered for each test to be performed because the consumer target group can be different from one test to the next, even for the same
47、 product. Has the product to be tested already been introduced on the market? If so, is it possible to distinguish between actual and potential consumers? Are the consumers of interest those who actually use the product, potential consumers who have not been using the product or both groups? Are res
48、ults from specified subgroups to be examined and compared? Are the results of the total consumer sample to be analysed with a view identifying subgroups? Are differences between the results of individuals of interest? 4.3 F urther specificati ons Subsequent to specifying the target population, the f
49、ollowing aspects shall be specified: place of test (see Clause 7); expected precision of measurement (see 6.1); test method (see Clause 9); product presentation plan for the test methods selected (see 10.2); specifications for the hypothesis to be tested (see 6.1);4 ISO 2014 All rights reserved ISO 11136:2014(E) For the hypothesis to be tested, the following aspects shall then be specified: the composition of the consumer sample(
