This International Standard describes a procedure allowing to determine whether there exists a perceptible sensory difference or a similarity between samples of two products concerning the intensity of a sensory attribute. This test is sometimes also referred to as a directional difference test or a 2-AFC test (Alternative Forced Choice). Indeed, the paired comparison test is a forced choice test between two alternatives.NOTE: The paired comparison test is the simplest existing classification test since it concerns only two samples.The method is applicable whether a difference exists in a single sensory attribute or in several, which means that it allows to