SENSORY DIFFERENCE TESTS: THURSTONIAN AND SSA PREDICTIONS FOR VANILLA FLAVORED YOGURTS

The Thurstonian prediction that judges will get a higher proportion of correct 3-AFC tests than triangle tests was confirmed using a yogurt system. As predicted, d' values for the triangle and 3-AFC tests corresponded. Sequential Sensitivity Analysis predictions for the sensitivity of various tasting sequences were confirmed for the 3-AFC test but not the triangle test. Further predictions that the 2-AFC is more sensitive than the 3-AFC were confirmed. This increase in sensitivity more than offset the greater statistical power of the 3-AFC. Difficulties of specifying the nature of the difference for the 2-AFC and 3-AFC tests were overcome using a warm-up procedure.