Variation in the manufacture of consumer products presents a challenge when investigating the suitability of process and formulation changes to a particular product. This issue is particularly relevant when investigating small sensory differences, like those involved in discrimination testing. In some cases, a product is best represented by several variants. The traditional discrimination protocols such as the triangular, duo-trio and m-alternative forced choice methods do not allow the consideration of manufacturing variation, unless multiple paired tests are performed. This approach can be costly and time-consuming. In an earlier newsletter, we introduced Torgerson’s method of triads. Using an appropriate model, this method allows for the simultaneous estimation of multiple product differences. In this report, we discuss a multivariate model for Torgerson’s method.
Rousseau, B. and Ennis, D. M. (2002). Multivariate Difference Testing with Multiple Samples. IFPress, 5(2) 2-3.
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Multivariate Difference Testing with Multiple Samples
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This technical report also appears in our book, Tools and Applications of Sensory and Consumer Science.