A/NOT A

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. Panelists are typically provided with a single sample (A or Not A) and tasked with indicating whether it is identical or different compared to the reference sample (A).

Template Description

The template starts with a screen giving instructions to panellists. In the design section, two options are available.
The first option applies to tests where panellists evaluate only the provided sample and indicate whether it is either A or Not A. 
The second option is for tests, where panellists assess both sample A and sample Not A before indicating whether the test sample is A or Not A. 
Following their choice, panellists can include a comment.
The end screen of the template features a thank-you message, offering the opportunity to customize a final message for panellists. 
In the design settings, you can review how each panellist will receive the sample, with each set corresponding to a specific order of presentation.
In this template, each panellist receives either product A or product Not A in monadic sequential order.

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 A sample or not. If the A sample was not recognized, the data will be recorded as a 0, whereas if the panellists correctly identified the A sample, the data will be recorded as a 1. The Q1_info column provides additional information about the products presented to the panellists. 
  1. If the panellist was presented with A and correctly identified the sample as A the result will be recorded as R1-1. 
  2. If the panellist was presented with A and incorrectly identified the sample as Not A the result will be recorded as R1~1.
  3. If the panellist  was presented with Not A and correctly identified the sample as Not A the result will be recorded as R1~2. 
  4. If the panellist was presented with Not A and incorrectly identified the sample as A the result will be recorded as R1~2.

Analysis

Once data has been gathered, you can access EyeOpenR and navigate to the Discrimination methods. Choose the A-Not A 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/a-not-a-analysis

References

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

    • Related Articles

    • Discrimination Analyses Overview

      Overview Difference tests are the fundamental and most frequently used methods in sensory and consumer research. The most important questions difference tests must answer are: do various products differ from each other? And does the consumer detect ...

    • 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 ...

    • 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 ...

    • 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 ...