Assessing the bias of preference, detection, and identification measures of discrimination ability in product design

Researchers often test consumers’ abilities to discriminate between two product formulations. Such tests are used in new product development, quality control, and competitive assessment. This paper investigates three paired comparison taste tests, each requiring a different judgment. These are: preference (‘Which of these two do you prefer?’), identification (‘Which one of these two is Brand X?’) and detection (‘Are these two products the same or different?’). Each task has biases that may influence the level of measured discrimination ability. As far as is known, this is the first empirical study to compare subject discrimination ability as measured by all three tasks. Additionally, the authors test two scales of subject confidence ratings and discuss implications for product testing.