ISO 5495:2005 pdf download.Sensory analysis -Methodology 一Paired comparison test.
7.4 Do no ask any questions about preference, acceptance or degree of difference following the selection of the most Intense sample. The selection the assessor has just made may bias the response to any additional questions. Responses to such questions may be obtained through separate tests concerning preference, acceptance, degree of difference. etc. (see ISO 6658). A ‘Comments section requesting the reasons for the choice may be included for the assessors remarks.
7.5 The paired test is a “forced choice procedure; assessors are not allowed to choose the “nO difference option. An assessor who detects no difference between the samples should be instructed to select one 01 the samples and to Indicate that the selection was only a guess en the ‘Comments section of the scoresheel
8 Analysis and interpretation of results
8.1 When testing for a difference
8.1.1 Case of a one-sided test
Use Table A.1 to analyse the data obtained from a paired test. If the number of correct responses is greater than or equal to the number given in Table A.1 (corresponding to the number of assessors and to the a-risk level chosen for the test), conclude that a perceptible difference exists between the samples (see B. 1).
If desired, calculate a confidence interval on the proportion of the population able to distinguish the samples This method is described in B.5.
No conclusion should be drawn for maximum numbers of correct responses under n12.
8.1.2 Case of a two-sided test
Use Table A.2 to analyse the data obtained from a paired test. If the number of consansual responses is greater than or equal to the number given in Table A.2 (corresponding to the number of assessors and to the u-risk level chosen for the test), conclude that a perceptible difference exists between the samples (see 8.3).
If desired, calculate a confidence interval on the proportion of the population able to distinguish the samples. This method is described en 8.5.
7.5 The paired test is a “forced choice procedure; assessors are not allowed to choose the “nO difference option. An assessor who detects no difference between the samples should be instructed to select one 01 the samples and to Indicate that the selection was only a guess en the ‘Comments section of the scoresheel
8 Analysis and interpretation of results
8.1 When testing for a difference
8.1.1 Case of a one-sided test
Use Table A.1 to analyse the data obtained from a paired test. If the number of correct responses is greater than or equal to the number given in Table A.1 (corresponding to the number of assessors and to the a-risk level chosen for the test), conclude that a perceptible difference exists between the samples (see B. 1).
If desired, calculate a confidence interval on the proportion of the population able to distinguish the samples This method is described in B.5.
No conclusion should be drawn for maximum numbers of correct responses under n12.
8.1.2 Case of a two-sided test
Use Table A.2 to analyse the data obtained from a paired test. If the number of consansual responses is greater than or equal to the number given in Table A.2 (corresponding to the number of assessors and to the u-risk level chosen for the test), conclude that a perceptible difference exists between the samples (see 8.3).
If desired, calculate a confidence interval on the proportion of the population able to distinguish the samples. This method is described en 8.5.
