The duo-trio test, developed by Peryam and Swartz (1950), represented an alternative to the triangle test that, for some, was a more complex test psychologically. The duo-trio test was found to be useful for products that had relatively intense taste, odor, and/or kinestethetic effects such that may impact sensitivity.
A Duo-Trio Test is an overall difference test which will determine whether or not a sensory difference exists between two samples. This method is particularly useful:
To determine whether product differences result from a change in ingredients, processing, packaging, or storage
To determine whether an overall difference exists, where no specific attributes can be identified as having been affected