SENSORY DISCRIMINATION TESTS

WHAT ARE SENSORY DISCRIMINATION TESTS?

When introducing a new product, discrimination testing is very important in sensory analysis. Sensory discrimination tests allow you to check if a product is significantly different from a second product. They include the triangle test, the duo-trio test, 2-AFC, and more!

SENSORY DISCRIMINATION TESTS IN XLSTAT

XLSTAT includes the most common discrimination test in sensory analysis.

Two models can be used to estimate the parameters of these tests:

• The Thurstonian model
• The guessing model

XLSTAT allows you to run:

• Triangle test: Three samples are presented to each assessor in different orders. Within these samples, two are similar and the third one is different. Assessors must identify the sample that is different from the others.
• Duo-trio test: Assessors taste a reference product. Then they taste two different products. Assessors must identify the product that is similar to the reference product.
• Two out of five test: Five samples are presented to the assessors. These samples are separated into two groups – the first group having three similar samples and the second group having two similar samples. The assessors must identify the group of two similar samples.
• 2-AFC test: Two products are presented to each assessor. The assessor must tell which product has the highest intensity on a particular characteristic.
• 3-AFC test: Three samples are presented to each assessor. Two are similar and the third one is different. The assessor must tell which sample has the highest intensity on a particular characteristic.
• Tetrad test: Four samples similar two by two are presented to each assessor. Each assessor must identify both groups of samples.

Each of these tests has its own advantages and drawbacks. A wide literature on the subject is available (Bi, 2008).

XLSTAT uses the psychometric functions and d' which allows you to select the distribution you want to use. Moreover, you can test the difference or the similarity between your products. The minimum (or maximum) number of answers to be significant is displayed.