ASTM E1885-04(2011)

This test method is effective for the following test objectives:

To determine whether a perceivable difference results or a perceivable difference does not result, for example, when a change is made in ingredients, processing, packaging, handling or storage; or

To select, train and monitor assessors.

This test method itself does not change whether the purpose of the triangle test is to determine that two products are perceivably different versus that the products are not perceivably different. Only the selected values of p_d, α, and β change. If the objective of the test is to determine if there is a perceivable difference between two products, then the value selected for α is typically smaller than the value selected for β. If the objective is to determine if the two products are sufficiently similar to be used interchangeably, then the value selected for β is typically smaller than the value selected for α and the value of p_d is selected to define “sufficiently similar.”

1.1 This test method covers a procedure for determining whether a perceptible sensory difference exists between samples of two products.

1.2 This test method applies whether a difference may exist in a single sensory attribute or in several.

1.3 This test method is applicable when the nature of the difference between the samples is unknown. It does not determine the size or the direction of the difference. The attribute(s) responsible for the difference are not identified.

1.4 Compared to the duo-trio test, the triangle test can achieve an equivalent level of statistical significance with fewer assessors. For details on how the triangle test compares to other three-sample tests, see Refs (1), (2), (3) and (4).

1.5 This test method is applicable only if the products are homogeneous. If two samples of the same product can often be distinguished, then another method, for example, descriptive analysis, may be more appropriate.

1.6 This test method is applicable only when the products do not cause excessive sensory fatigue, carryover or adaptation.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.