The rating test is a check for differences which is used frequently for products which, in regard to the concentration, vary in one characteristic. For this, all the samples are ordered at random and have subsequently to be put into the correct order. With the help of this test, the sensitivity and the suitability of the examiners for sensory evaluation can be checked.
In practice, for example, the salt content of bread from 1.6 to 2.4 % (calculated based on flour) could be tested by increasing in intervals of 0.2 %. Also for the comparison of plain cakes with one another with a different content of sugar, a rating test can be meaningful. This test is also applied for the recognition and rating of different colour scales of diluted solutions (red/yellow) or the firmness of bodies. In addition, test series are also possible which should be rated according to preference. Are the differences only small, strong fluctuations of the results within a test series can appear, as one fault can result in another.