Sensory Evaluation Techniques & Methodologies Flashcards

In a standard triangle test, what is the probability of a correct response by chance alone?

Answer: 1/3

With three samples and one odd sample, a guessing assessor picks correctly one time in three.

In a duo-trio test, what is the assessor asked to do?

Answer: Identify which of two coded samples matches an identified reference

Duo-trio presents a labeled reference followed by two coded samples, one of which matches the reference.

Why is the tetrad test often preferred over the triangle test for unspecified difference testing?

Answer: It has greater statistical power, so fewer assessors are needed for the same sensitivity

The tetrad has the same 1/3 guessing probability as the triangle but is more powerful in Thurstonian terms.

What is the chance probability of a correct answer in the two-out-of-five test?

Answer: 1/10

There are ten ways to choose two samples from five, so a guess is right only 1 time in 10.

A directional paired comparison asks 'Which sample is sweeter?' when the developer expects sample B to be sweeter. What type of statistical test fits?

Answer: One-tailed binomial test with p = 1/2

When the expected direction is known in advance, a one-tailed test at p = 1/2 is appropriate.

Which difference test suits samples with a strong, lingering aftertaste, where tasting three or more samples would cause fatigue?

Answer: Same-different (simple difference) test

The same-different test uses only two samples per trial, which limits carryover and fatigue.

When is the A-not-A test most appropriate?

Answer: When samples cannot be presented at the same time or vary slightly in appearance

In A-not-A, assessors learn sample A and then judge coded samples one at a time, so the samples never need to be presented together.