Importance of Correct Instructions in the Tetrad Test

• Published in: Journal of sensory studies 2013-08, Vol.28 (4), p.264-269
• Main Authors: Rousseau, Benoît, Ennis, John M.
• Format: Article
• Language: English
• Subjects: Studies
• ISSN: 0887-8250; 1745-459X
• DOI: 10.1111/joss.12049

Use of the tetrad test has increased recently as both theoretical and experimental results have shown that it is statistically more powerful than the triangle test. In this article, although, we show that this power advantage depends on the choice of instructions. Specifically, we show that if experimenters ask respondents to select the two most similar samples out of four, instead of asking respondents to group the four samples into two groups of two based on similarity, then the resulting test will have approximately the same power as the triangle test. This fact serves as a reminder of the importance of correct test instructions in difference testing, as specific wording can clearly affect a test power and thus the final conclusion of an investigation. Practical Applications Businesses are increasingly considering the tetrad test as an alternative to the triangle test within their difference testing programs. This article clarifies the correct test instructions for the tetrad test, and shows that its power advantage over the triangle test will be compromised if incorrect instructions are given. Thus, it is essential that practitioners provide correct task instructions in order to realize the full potential of the tetrad test.