Caroline Peltier , Alix Rollinat , Christophe Martin
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引用次数: 0
Abstract
The r-Alternative Forced Choice (r-AFC) test is a test of discrimination in which the subject is presented with three samples, one of which is a test sample containing a nominated stimulus (test sample), the other being references. The subject is instructed to indicate the test sample. Taste and odor sensitivity thresholds are frequently determined using successive r-AFC tests with stimuli in increasing concentrations. The Best Estimate Threshold (BET) method consists in using successive 3-AFC with increasing concentrations to estimate sensitivity threshold. Then, the threshold is estimated using the geometrical mean of the highest concentration that caused an error and the concentration directly below it. However, a subject who feels no difference between the samples may give a correct answer by chance. It leads to consequent potential bias in the determination of the sensitivity thresholds.
This paper aims to formalize and model the thresholds obtained in successive r-AFC in order to quantify the errors inherent in such protocols. It establishes that, when you assumed that the distribution of the true sensitivity threshold is known in the population, the threshold obtained by r-AFC can be modelled with a variable following a specific probability law.
This paper presents the theory of this model, then illustrate it with simulations and application on a real dataset. An R package dedicated to these analyses, AFCR, was also created and is available on github (https://github.com/ChemoSens/AFCR). Therefore, sensory scientists could use the package as a help to set up their sensory protocol or-to analyze their own data.
期刊介绍:
Food Quality and Preference is a journal devoted to sensory, consumer and behavioural research in food and non-food products. It publishes original research, critical reviews, and short communications in sensory and consumer science, and sensometrics. In addition, the journal publishes special invited issues on important timely topics and from relevant conferences. These are aimed at bridging the gap between research and application, bringing together authors and readers in consumer and market research, sensory science, sensometrics and sensory evaluation, nutrition and food choice, as well as food research, product development and sensory quality assurance. Submissions to Food Quality and Preference are limited to papers that include some form of human measurement; papers that are limited to physical/chemical measures or the routine application of sensory, consumer or econometric analysis will not be considered unless they specifically make a novel scientific contribution in line with the journal''s coverage as outlined below.