Journal Articles

Journal Article: Sensory discrimination testing and consumer relevance (2015)

Abstract: In order to ensure consistency in the decision making process over time, a discrimination testing program must take into account all of five elements: The testing protocol, the sample size, the Type I error (α), the Type II error (β) (power = 1 - β) and a measure of the threshold above which...

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Journal Article: A Thurstonian model for the degree of difference protocol (2015)

Abstract: In the degree of difference methodology (DOD), subjects are presented with pairs of samples, either identical or different, and must indicate how different the samples are using a t-point category rating scale. In this article, the Thurstonian model for the DOD assuming independent assessments is derived. The model permits the estimation of the...

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Journal Article: A Thurstonian comparison of the Tetrad and Degree of Difference tests (2015)

Abstract: The recurring need to assess product reformulations has kept difference testing at the forefront of sensory science. Within the realm of difference testing, the Tetrad test has risen in popularity recently as its superiority over the Triangle test has been demonstrated both in theory and in practice. But it remains to compare the...

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Journal Article: Sensory difference tests as measurement instruments: A review of recent advances (2014)

Abstract: In the evaluation of new incarnations of existing products, difference testing is among the most commonly used sensory techniques. However, although difference testing is a classical technique, the science of difference testing continues to evolve. As Thurstonian analysis has gained increased acceptance for its ability to measure sensory differences, recent research advances have...

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Journal Article: Triangle and tetrad protocols: Small sensory differences, resampling and consumer relevance (2014)

Abstract: The objective of this research was twofold: first, the performance of the tetrad protocol was compared to that of the triangle test under conditions that could possibly lower its sensitivity, consequently resulting in the loss of its theoretical power advantage. Second, the same samples were compared with a preference test to investigate whether...

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Journal Article: Paired preference data with a no-preference option – Statistical tests for comparison with placebo data (2014)

Abstract: It is well-established that when respondents are presented with identical samples in a preference test with a no preference option, a sizable proportion of respondents will report a preference. In a recent paper (Ennis, D. M., & Ennis, J. M. (2012a). Accounting for no difference/preference responses or ties in choice experiments. Food Quality...

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Journal Article: Precision of measurement in Tetrad testing (2014)

Abstract: Interest in the Tetrad test has increased recently as it has become apparent that this methodology can be a more powerful alternative to the Triangle test within the standard difference testing paradigm. But when products are tested following an ingredient or process change, a pressing question is whether a sensory difference is large...

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Journal Article: Transitioning from proportion of discriminators to a more meaningful measure of sensory difference (2014)

Abstract: A commonly used approach for quantifying effect sizes in sensory difference testing is the so-called "Proportion of Discriminators" or "Proportion of Distinguishers" model. Such effect sizes are quantified by determining the proportion of discriminators in the population via a transformation of the proportion of correct responses in the difference test. This model has...

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Journal Article: Reconsidering the specified tetrad test (2013)

Abstract: Additional noise from additional stimuli has been shown to result in a loss of operational power in sensory difference tests. Because the Specified Tetrad test requires the evaluation of four stimuli and has only a slight theoretical power advantage over the two-alternative forced choice (2-AFC), Ennis and Jesionka have argued that the Specified...

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Journal Article: Mapping hedonic data: A process perspective (2013)

Abstract: Multivariate analyses are commonly used to study differences among items in a multidimensional space and to relate these findings to hedonic assessments of the same items. But there are numerous methods in use and the purpose of this article is to review these methods from a process standpoint. Specifically, this article considers the...

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