Sensory discrimination tests
Sensory discrimination tests allow to test if a product is different from another. They are available in Excel using the XLSTAT statistical software.
What are sensory discrimination tests?
When introducing a new product, discrimination testing are very important in sensory analysis. Sensory discrimination tests allow to check if a product is significantly different from a second product. They include the triangle test, the duo-trio test, 2-AFC…
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: 3 samples are presented to each assessor in different orders. Within these samples, two are similar and the third one is different. Assessors have to 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 in two groups, the first one having three similar samples and the second one having two similar samples. The assessors have to identify the group of two similar samples.
- 2-AFC test: 2 products are presented to each assessor. The assessor has to tell which product has the highest intensity on a particular characteristic.
- 3-AFC test: 3 samples are presented to each assessor. Two are similar and the third one is different. The assessor has to 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 has two 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' and allows you to select the distribution you want to use.