WINE TASTER ON 03/09/98 WITH 6 JUDGES AND 4 WINES BASED ON RANKS Copyright (c) 1994-97 Richard E. Quandt FLIGHT 1: Number of Judges = 6 Number of Wines = 4 Identification of the Wine: The judges''s overall ranking: Wine A is Jos. Phelps Cab.1977 ........ 1st place Wine B is Jos. Phelps Cab.1979 ........ 3rd place Wine C is Jos. Phelps Cab.1978 ........ 2nd place Wine D is Jos. Phelps Cab.1976 ........ 4th place The Judges'' Rankings Judge Wine -> A B C D Grant S. 1. 3. 4. 2. Frank V. 1. 4. 3. 2. Orley A. 3. 1. 2. 4. John L. 1. 2. 3. 4. Burt M. 3. 4. 1. 2. Richard Q. 2. 3. 1. 4. Table of Votes Against Wine -> A B C D Group Ranking -> 1 3 2 4 Votes Against -> 11 17 14 18 ( 6 is the best possible, 24 is the worst) Here is a measure of the correlation in the preferences of the judges which ranges between 1.0 (perfect correlation) and 0.0 (no correlation: W = 0.1667 The probability that random chance could be responsible for this correlation is rather large, 0.3916. Most analysist would say that unless this probability is less than 0.1, the judges preferences are not strongly related. We now analyze how each tasters'' preferences are correlated with the group preference. A correlation of 1.0 means that the taster''s preferences are a perfect predictor of the group''s preferences. A 0.0 means no correlation, while a -1.0 means that the taster has the reverse ranking of the group. Correlation Between the Ranks of Each Person With the Average Ranking of Others Name of Person Correlation Orley A. 0.4000 Burt M. 0.3162 Grant S. 0.1054 John L. -0.4000 Frank V. -0.4000 Richard Q. -0.7379 The wines were preferred by the judges in the following order. When the preferences of the judges are strong enough to permit meaningful differentiation among the wines, they are separated by ------------------- and are judged to be significantly different. 1. ........ 1st place Wine A is Jos. Phelps Cab.1977 2. ........ 2nd place Wine C is Jos. Phelps Cab.1978 3. ........ 3rd place Wine B is Jos. Phelps Cab.1979 4. ........ 4th place Wine D is Jos. Phelps Cab.1976 Comments: Comments by Orley Ashenfelter--tasting took place February 9, 1998: This was a tasting of 4 adjacent vintages of California cabernet sauvignon from a very reliable California producer in the 1970s. All the wines were served in magnums blind. These vintages in California (1976-79) have very different reputations for quality. The goal was to see whether the vintages are really different. The answer, felt strongly by all present, is no! The wines were outstanding drinking and of remarkable consistency. However, these wines are ready to drink now. I noticed after the tastng that my own ranks are perfectly predicted by the age of the wine: I tended to like the slightly younger (and fresher) wines, somewhat to my own surprise! Drink up.