ISO 8587:2006 pdf download.Sensory analysis — Methodology 一Ranking.
b) untrained assessors or consumers, already trained on the method
1) for hedonic preference,
2) when pre-sorting samples (to select a few products from a large number, as a preliminary test). For the conditions th which assessors shall comply, see ISO 6658, ISO 8586-1 and ISO 8586-2 They shaM all be specially trained on the ranking procedure and on the selected descriptors being used.
6.2 Number of assessors
The number of assessors depends on the aim of the test (see Annex A).
When testing assessors’ performance, training assessors or determining perception thresholds of individuals or groups, no minimum or maximum number is required.
For descflptive product assessment, the minimum number of assessors is determined by the levels of statistical risks accepted and shall comply with ISO 11035 or ISO 11036, ie. preferably around 12 to 15 selected assessors.
For determining the order of preference in a hedonic test, the minimum number of assessors is determined by the levels of statistical risks accepted, e.g. a minimum of 60 assessors per group of consumer type
For statistical analysis of the results, other things being equal (for example, test conditions, qualification of assessors), the larger the number of assessors, the greater the probability of revealing any systematic difference ii rank among products.
6.3 Preliminary discussion
The assessors shall be informed of the purpose of the test, i.e. ranking of test samples.
If necessary. a demonstration of a ranking procedure can be given. It is essential in this test to ensure common understanding by ci assessors of the criterion under test The preliminary discussion shaM not influence assessors’ expectations.
1) for hedonic preference,
2) when pre-sorting samples (to select a few products from a large number, as a preliminary test). For the conditions th which assessors shall comply, see ISO 6658, ISO 8586-1 and ISO 8586-2 They shaM all be specially trained on the ranking procedure and on the selected descriptors being used.
6.2 Number of assessors
The number of assessors depends on the aim of the test (see Annex A).
When testing assessors’ performance, training assessors or determining perception thresholds of individuals or groups, no minimum or maximum number is required.
For descflptive product assessment, the minimum number of assessors is determined by the levels of statistical risks accepted and shall comply with ISO 11035 or ISO 11036, ie. preferably around 12 to 15 selected assessors.
For determining the order of preference in a hedonic test, the minimum number of assessors is determined by the levels of statistical risks accepted, e.g. a minimum of 60 assessors per group of consumer type
For statistical analysis of the results, other things being equal (for example, test conditions, qualification of assessors), the larger the number of assessors, the greater the probability of revealing any systematic difference ii rank among products.
6.3 Preliminary discussion
The assessors shall be informed of the purpose of the test, i.e. ranking of test samples.
If necessary. a demonstration of a ranking procedure can be given. It is essential in this test to ensure common understanding by ci assessors of the criterion under test The preliminary discussion shaM not influence assessors’ expectations.
