Three-Alternative Forced Choice (3-AFC)

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 attribute. The specified sensory attribute should be the sole perceptible difference between the two samples. 
The 3-AFC test enables sensory scientists to determine whether the two samples vary in the specified sensory attribute and which sample has a higher perceived intensity of the specified attribute. However, there is a risk that modifications to one attribute may lead to other sensory changes in the food, potentially obscuring the attribute in question.

Template Description

The template starts with a screen giving instructions to panellists. In the design section, the first screen has instructions, followed by a question where participants pick the more intense product in a specific attribute (e.g., sweetness). After choosing, panellists can add comments.
On the end screen, the template incorporates a thank-you message, providing an opportunity for you to personalize a final message for the panellists. 
Within the design settings, you can examine how each panellist will receive the sample, with each set corresponding to a specific order of presentation for an individual panellist.
Within this template, Product 1 functions as the original product, while Product 2 represents the new product (e.g., one with a reduced sucrose level). You have the flexibility to edit these fields by clicking on the Product section.

Raw Data Representation

The raw data will be displayed, with each row corresponding to an individual judge and the pair of products they were presented with. The data will be stored to indicate whether the panellists correctly identified the odd sample or not. If the odd sample was not recognized, the data will be recorded as a 0, whereas if the panellists correctly identified the odd sample, the data will be recorded as a 1. The Q1_info column provides additional information about the products presented to the panellists, with the selection made by the panellists added in brackets.

Analysis

Once data has been gathered, you can access EyeOpenR and navigate to the Discrimination methods. Choose the 3AFC analysis to examine your results. Additional details about this analysis can be found in the following article: https://support.eyequestion.nl/portal/en/kb/articles/2-2-afc-3-afc-duo-trio-triangle-tetrad 

References

  1. Reference: Lawless, H. T., & Heymann, H. (2010)

    • Related Articles

    • 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 ...

    • 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 ...

    • 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 ...

    • Free Choice Profiling

      Introduction Free-choice profiling (FCP) is a quick and inexpensive method in which consumers are asked to both identify attributes in the sample and rate the liking and/or intensity of those attributes. They should be provided with adequate ...

    • 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 ...