In a previous technical report we discussed
a commonly used measure of sensory difference, the
proportion of discriminators (Pd), and explained that this
measure is method specific. We concluded that:
“The concept of the proportion of discriminators is intuitive and appealing. Unfortunately, it is also method-specific and one can achieve very different values using different methods, which reduces its appeal as a management criterion. The use of a method–independent index, such as the Thurstonian d', can provide more stable and accurate information that may be valuable in a decision that involves the consideration of consumers’ ability to discriminate between alternate product formulations.”
Many companies have implemented sensory discrimination
programs using Pd as a parameter for power calculations.
Since this measure has shortcomings, there is a need to
consider a unit that is method-independent such as the
Thurstonian . Fortunately, tools exist that permit the
translation of a method-specific Pd into the corresponding
value. In this report we discuss how these tools can be
used in practice.
This technical report appears as:
Rousseau, B., Ennis, D. M., and Ennis, J. M. (2013). Transitioning from Proportion of Discriminators to Thurstonian Delta. IFPress, 16(2) 3-4.
Download this technical report here:
Not a Colleague? Click here to join for free!
This technical report also appears in our book, Tools and Applications of Sensory and Consumer Science.