## Those random wine medals

September 1, 2009
abstract, full paper) that there's really no such thing as "wine quality", if you're tasting blind:

Bob Hodgson provides yet more evidence (abstract, full paper) that there’s really no such thing as “wine quality”, if you’re tasting blind:

An analysis of over 4000 wines entered in 13 U.S. wine competitions shows little concordance among the venues in awarding Gold medals… An analysis of the number of Gold medals received in multiple competitions indicates that the probability of winning a Gold medal at one competition is stochastically independent of the probability of receiving a Gold at another competition…

For the 375 wines entered in five competitions, one would expect by chance alone (for p = 0.09), 234 wines receiving no Golds, 116 receiving a Gold in just one competition, 23 receiving Golds in two competitions, two receiving Golds in three competitions and no wine receiving Golds in more than three competitions. The observed frequencies closely mirror these numbers.

The more I look at empirical studies such as this one, the more I’m convinced that if you’re tasting blind, there’s no correlation between perceived quality and just about anything. On the other hand, we almost never taste blind in real life — and when you know what you’re drinking, there’s are very strong correlations between perceived quality and lots of things, such as provenance, price, and even whether the wine has a screw cap or a cork.

Which is why it’s perfectly rational to order expensive wine in a restaurant: since you know what you’re drinking, and how much it costs, there’s a very good chance that you’ll enjoy the more expensive wine more and the less expensive wine less. If you tasted them blind, on the other hand, there would be no correlation there at all.