The latent distribution of a rating observed

Abstract

ABSTRACT While extensive literature shows that the rating assigned by a critic or judge to a wine is one draw from a latent distribution, little has been published about the shape of that distribution. This article presents a derivation and test of a discrete and bounded probability mass function (PMF) that describes the distribution of the rating that a judge assigns to a wine. That PMF and the ratings that 72 wine judges assigned to blind triplicates in a commercial wine competition show that judges’ ratings are not identically distributed and that variance in ratings is a function of both the wine and the judge. Some wines are more difficult to rate consistently than others. Seventy percentage of judges reduce the variance due the wine alone, the standard deviation of the rating that a judge assigns averages 1.3 out of 10 ratings, and that deviation is significantly less than the standard deviation of random draws. The PMF and those results can be employed to improve wine-related and perhaps other taste-related research by considering the latent distribution that surrounds a rating observed.