Two Out of Five

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 that differ from the other three.
This test has a 1 in 10 chance of being correct by random guess. Its main advantage is the low chance of randomly choosing the right pair.
However, a significant drawback is the potential for sensory fatigue, especially with samples that need to be smelled and tasted. It works well for samples compared visually, by touch, or by hearing.
It's recommended to use a limited number of judges, usually between 10 and 20.

Template Description

The template starts with a screen, which can be used for welcoming panellists or asking additional questions prior to the test. In the design section, the first screen has instructions specific to the task, followed by a question where participants are presented with five blinded coded samples and are asked to indicate which of the five are the same. Participants can only select two samples. Once the task is completed, panelists have the opportunity to add comments. This option can be utilized if panelists wish to provide reasoning for their choice.
In 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. The test employs a block design, presenting five samples simultaneously to the panelists. The order of presentation is randomized across all sets/panellists. 

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 selected the identical samples or not. If the answer is incorrect, the data will be recorded as a 0, whereas if the panellists answer correctly, the data will be recorded as a 1. The Q1_info column provides additional information about the order of samples provided to the panellists and the answers selected.

References

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

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