BAYESIAN APPROACH TO SENSORY PREFERENCE, DIFFERENCE AND EQUIVALENCE TESTS.

ABSTRACT Bayesian theory provides another philosophy of statistics and reasoning for data analysis. It offers an alternative to classical statistical inference. Bayesian approach is of theoretical and methodological significance to sensory discipline and has potentially wide application in sensory and consumer research. This paper discusses Bayesian approach to nonreplicated sensory preference, difference and equivalence tests based on proportions. Bayesian approach to the tests involves Bayesian inference for one proportion with and without background effect (i.e., guessing probability) and for two proportions. Thurstonian discriminal distance d′ is used for measure of sensory difference in Bayesian approach. A set of R and S-Plus codes implementing the Bayesian estimates and tests introduced in the paper is available from the supporting information in the online version of this paper. PRACTICAL APPLICATIONS Sensory preference, difference and equivalence tests are widely used in sensory analysis and consumer research. Bayesian approach provides an alternative to classical statistical inference for the tests. If sample size is large enough or prior distribution is less informative, the results from classical statistical inference and Bayesian approach may not differ greatly; while if sample size is small and prior distribution is more informative, the results may be dramatically different. [ABSTRACT FROM AUTHOR]