Discrimination Methods
Two-Alternative Forced Choice (2-AFC)
Introduction The Two-Alternative Forced Choice (2-AFC) method, is a specific way of comparing two samples in sensory science. In this method, the only allowed difference between the two samples is a specified sensory characteristic. It works well ...
Three-Alternative Forced Choice (3-AFC)
Introduction The three-alternative forced choice (3-AFC) method is a discrimination method where panelists are presented with three samples simultaneously and instructed to identify the sample(s) that are higher or lower in a specified sensory ...
A/NOT A
Introduction In sensory testing, A-not-A tests are used to evaluate the sensory discrimination ability of individuals when presented with different products. These tests aim to determine whether individuals can discern variations between two products ...
Different From Control
Introduction The difference-from-control test is used to quantify differences between a tested sample and a control sample. This method is particularly applicable when comparing products with a single sensory attribute or only a few varying sensory ...
Two Step Double-Faced Applicability Test
Introduction In the 'double-faced applicability' test, each attribute is presented with a “double-faced” approach, featuring two descriptors (a pair of semantic-differential descriptors) separately presented in the questionnaires to represent both ...
Duo-Trio
Introduction 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 ...
Same-Different
Introduction During a Same-Different test, each panellist is presented with two (equal or different) products or samples. The panellist must state whether the products are equal or different. This method is used to determine whether a sensory ...
Tetrad
Introduction The Tetrad method is a testing procedure designed to understand the presence of a perceptible sensory distinction between two products. Panelists are given four samples, with two being identical and two being different. The panellists ...
Triangle
Introduction The triangle method is used to understand the presence or absence of a perceptible sensory difference or similarity between samples of two products through a forced-choice approach. Participants are presented with three samples, two of ...
R-Index
Introduction The R-index is a tool in sensory science that helps quantify the difference between two samples. The R-index is designed to quantify the area under an empirical Receiver Operating Characteristics (ROC) curve within the framework of ...
Two Out of Five
Introduction The Two Out of Five method is used to understand the presence or absence of a perceptible sensory difference or similarity between samples of two products. Panellists are presented with five samples and asked to identify the two samples ...
Paired Comparison
Introduction The paired comparison method is a handy method to use when dealing with products that have a lasting effect or are in short supply. Unlike other tests like the triangle or duo-trio, it works well when showing three samples at once isn't ...
Popular Articles
2-AFC, 3-AFC, Duo Trio, Triangle, Tetrad Analysis
Purpose Analyse results from one of the following tests: 2-AFC, 3-AFC, Duo-Trio, Triangle, Tetrad. Data Format Discrimination.xlsx Results of the discrimination test are binary (1 = correct answer, 0 = incorrect answer) Background 2-AFC Test This is ...
Discrimination Test Settings - Pd and d' Analysis
Purpose Establish the power of a discrimination test given a set sample size or to calculate the sample size required to get a desired power. This can be done specifying the expected difference as a proportion of discriminators (Pd) or as a ...
How Can I Import a Custom Design?
How Can I Import a Custom Design? If your preferred design cannot be created using the design generator, a custom design can be created using excel and imported into an EQ project. To import a custom design, go to the design page of your project. ...
How Do I Generate an Experimental Design
In EyeQuestion you can generate different kind of experimental design. Some experimental designs are already included in the application, while specific ones can be imported. In the following article you will find more information on this kind of ...
How to Modify a Design from Monadic Sequential to Block Design
Introduction When creating a questionnaire, it could occur that you need to modify a design that initially presents samples to panelists in a monadic sequential order and instead switch to a block design where all samples are presented at once. In ...