The Duo-Trio Test is a sensory test that can determine the presence or absence of sensory differences between two samples. This method is particularly valuable in:
The Duo-Trio test can be comparable to the triangle test, maintaining simplicity and ease of comprehension. In contrast to the Paired Comparison test, it offers the advantage of presenting a reference sample. However, it requires the tasting of three samples as opposed to two, which may be considered a drawback.
The procedure involves presenting each subject with a clearly identified reference sample, followed by two coded samples, one of which corresponds to the reference. Subjects are then asked to identify the coded sample that matches the reference.
Two design options are available for the Duo-Trio test. 
  1. Duo-Trio Balanced Reference: This approach involves balancing the reference between the control and test products.
  2. Duo-Trio Constant Reference: This approach involves keeping the reference constant throughout the test.

Template Description

The template starts with a screen giving instructions to panellists. In the design section, the first screen includes one instruction question type, followed by a question where participants can select which of the samples is the same as the reference of the two provided. After choosing, panellists can add comments.
On the end screen, the template incorporates a thank-you message, providing an opportunity for you to personalize a final message for the panellists. 
Within the design settings, you can examine how each panellist will receive the sample, with each set corresponding to a specific order of presentation for an individual panellist. The Duo-Trio design contains two products that are presented at the same time. 
Within the Duo-Trio Balanced Reference template, Product 1 and Product 2 are balanced in terms of being the reference for each set. 
Within the Duo-Trio Constant Reference template, Product 1 is the constant reference.

Raw Data Representation

The raw data will be displayed, with each row corresponding to an individual judge and the pair of products they were presented with. The data will be stored to indicate whether the panellists correctly identified the odd sample or not. If the odd sample was not recognized, the data will be recorded as a 0, whereas if the panellists correctly identified the odd sample, the data will be recorded as a 1. The Q1_info column provides additional information about the products presented to the panellists, with the selection made by the panellists added in brackets.


Once data has been gathered, you can access EyeOpenR and navigate to the Discrimination methods. Choose the Duo Trio analysis to examine your results. Additional details about this analysis can be found in the following article: https://support.eyequestion.nl/portal/en/kb/articles/2-2-afc-3-afc-duo-trio-triangle-tetrad.


  1. Lawless, H. T., & Heymann, H. (2010)
  2. Meilgaard, M., G. V. Civille and B. T. Carr (2007). Sensory Evaluation Techniques, 4th Ed. New Boca Raton, FL: CRC Press, 6: 72 – 79.
  3. Stone, H., Bleibaum, R.N., and Thomas, H.  (2012). Sensory Evaluation Practices, 4th edition. Elsevier Academic Press, San Diego, CA, 5: 174-176.

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