Sample context effect in acceptability rating of beverages: Are hedonic ratings absolute in evaluative sets with outlier samples?

The effect of large differences across samples served in the same evaluative set in a consumer acceptance test design has yet to be examined. In this study, tea and cola products were used to determine the effect of including a significantly different sample, namely an outlier, in a set of samples that are similar in liking. An additional consumer test with orange juice products was conducted to determine the effects of an outlier being more liked or less liked compared to the other samples, and the outlier being served randomly versus fixed at a given presentation position. Results showed that including a less-liked outlier in an evaluative set did not create a context effect; thus, the liking ratings of other samples were not compressed toward the high end of the hedonic scale. However, including an outlier in the first serving position resulted in a higher discrimination of other samples. Fixing an outlier in the last serving position resulted in significantly lower scores for less-liked outliers, but no difference for more-liked outliers. In conclusion, contrast effect is minimal when created by the presence of an outlier in an evaluative set, where liking scores display a rather absolute behavior. Practical application: These findings demonstrate that acceptance ratings of similar samples are not significantly influenced by the presence of a sample outlier. Liking scores of the beverages tested in this study therefore seem to be absolute. This contrasts with previous literature on intensity ratings, which are comparative in nature and prone to bias caused by context effect. When considering whether to include a sample outlier (such as a highly different competitor product) in a consumer test of similar samples (for example, different prototypes of the same product), researchers may do so randomized within the same evaluative set.