WINETASTER ON 11/07/11 WITH 8 JUDGES AND 8 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2011 Richard E. Quandt, V. 1.65

FLIGHT 1: Number of Judges = 8 Number of Wines = 8

Identification of the Wine: The judges' overall ranking:

Wine A is Chambertin Clos de Bèze 1990 P. Gelin ........ 5th place Wine B is Clos de la Roche 2003 Girardin ........ 2nd place Wine C is Clos de la Roche 1995 Ponsot ........ 8th place Wine D is Chambertin Clos de Bèze 2003 Drouhin ........ 1st place Wine E is Clos de la Roche 1999 Amiot ........ 4th place Wine F is Chambertin Clos de Bèze 1995 Jadot ........ 3rd place Wine G is Clos de la Roche 1990 Dujac ........ 6th place Wine H is Chambertin Clos de Bèze 1999 Faiveley ........ 7th place

The Judges's Rankings

Judge Wine -> A B C D E F G H Alexa 6. 4. 8. 3. 1. 2. 5. 7. Zaki 4. 3. 5. 2. 6. 1. 8. 7. Orley 7. 8. 5. 4. 6. 1. 2. 3. Burt 2. 3. 8. 1. 4. 5. 6. 7. Bob 1. 3. 8. 2. 5. 6. 7. 4. Ed 7. 1. 8. 2. 3. 5. 6. 4. Mike 7. 2. 3. 4. 5. 6. 1. 8. Dick 3. 2. 5. 1. 4. 6. 8. 7.

Table of Votes Against Wine -> A B C D E F G H

Group Ranking -> 5 2 8 1 4 3 6 7 Votes Against -> 37 26 50 19 34 32 43 47

( 8 is the best possible, 64 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 = 0.2887

The probability that random chance could be responsible for this correlation is quite small, 0.0236. Most analysts would say that unless this probability is less than 0.1, the judges' preferences are not strongly related. We now analyze how each taster's 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. This is measured by the correlation R.

Correlation Between the Ranks of Each Person With the Average Ranking of Others

Name of Person Correlation R Burt 0.8333 Dick 0.6905 Alexa 0.6429 Zaki 0.5952 Ed 0.5714 Bob 0.3832 Mike -0.0476 Orley -0.4286

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 D is Chambertin Clos de Bèze 2003 Drouhin --------------------------------------------------- 2. ........ 2nd place Wine B is Clos de la Roche 2003 Girardin 3. ........ 3rd place Wine F is Chambertin Clos de Bèze 1995 Jadot 4. ........ 4th place Wine E is Clos de la Roche 1999 Amiot 5. ........ 5th place Wine A is Chambertin Clos de Bèze 1990 P. Gelin 6. ........ 6th place Wine G is Clos de la Roche 1990 Dujac --------------------------------------------------- 7. ........ 7th place Wine H is Chambertin Clos de Bèze 1999 Faivelet 8. ........ 8th place Wine C is Clos de la Roche 1995 Ponsot We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 16.1667. The probability that this could happen by chance is 0.0236 We now undertake a more detailed examination of the pair-wise rank correla- tions that exist between pairs of judges. First, we present a table in which you can find the correlation for any pair of judges, by finding one of the names in the left hand margin and the other name on top of a column. A second table arranges these correlations in descending order and marks which is significantly positive significantly negative, or not significant. This may allow you to find clusters of judges whose rankings were particularly similar or particularly dissimilar. Pairwise Rank Correlations Correlations must exceed in absolute value 0.74 for significance at the 0.05 level and must exceed 0.64 for significance at the 0.1 level Alexa Zaki Orley Alexa 1.000 0.405 0.071 Zaki 0.405 1.000 -0.071 Orley 0.071 -0.071 1.000 Burt 0.524 0.548 -0.429 Bob 0.143 0.357 -0.500 Ed 0.595 0.286 -0.238 Mike 0.048 -0.119 -0.095 Dick 0.286 0.619 -0.690 Burt Bob Ed Alexa 0.524 0.143 0.595 Zaki 0.548 0.357 0.286 Orley -0.429 -0.500 -0.238 Burt 1.000 0.833 0.524 Bob 0.833 1.000 0.452 Ed 0.524 0.452 1.000 Mike -0.048 -0.405 0.095 Dick 0.810 0.690 0.500 Mike Dick Alexa 0.048 0.286 Zaki -0.119 0.619 Orley -0.095 -0.690 Burt -0.048 0.810 Bob -0.405 0.690 Ed 0.095 0.500 Mike 1.000 0.048 Dick 0.048 1.000 Pairwise correlations in descending order 0.833 Burt and Bob Significantly positive 0.810 Burt and Dick Significantly positive 0.690 Bob and Dick Significantly positive 0.619 Zaki and Dick Not significant 0.595 Alexa and Ed Not significant 0.548 Zaki and Burt Not significant 0.524 Burt and Ed Not significant 0.524 Alexa and Burt Not significant 0.500 Ed and Dick Not significant 0.452 Bob and Ed Not significant 0.405 Alexa and Zaki Not significant 0.357 Zaki and Bob Not significant 0.286 Alexa and Dick Not significant 0.286 Zaki and Ed Not significant 0.143 Alexa and Bob Not significant 0.095 Ed and Mike Not significant 0.071 Alexa and Orley Not significant 0.048 Mike and Dick Not significant 0.048 Alexa and Mike Not significant -0.048 Burt and Mike Not significant -0.071 Zaki and Orley Not significant -0.095 Orley and Mike Not significant -0.119 Zaki and Mike Not significant -0.238 Orley and Ed Not significant -0.405 Bob and Mike Not significant -0.429 Orley and Burt Not significant -0.500 Orley and Bob Not significant -0.690 Orley and Dick Significantly negative

COMMENT: The wines as whole were tremendous and the differences were secondary to the overall pleasure that the group had from drinking them. There were few if any full or partially full glasses left on the table. Having said all that, 2003 was a clear winner in the tasting in both appellations. The design of this winetasting was to permit comparison of vineyards and vintages.We first note that the overall agreement in the group was very strong. The rank sums themselves can be summed in two ways: over vintages and over appellations. Doing this the first way, we get rank sums of 80, 82, 81 and 45 for 1990, 1995, 1999 and 2003 respectively. Doing it the other way we get 153 for Clos de la Roche and 135 for Chambertin. While the difference in the ranksums over appellations is not significant (although Chambertin edges out Clos de la Roche), and while the sum of rank sums for 1990, 1995 and 1999 are essentially identical, 2003 is rated significantly better than the other three vintages (See Richard E. Quandt,The Journal of Wine Economics, May 2007, pp. 98-102), which is further interesting because the 2003 wines were marginally less expensive than the others. What is further convincing evidence that the vintage effects are much more important than the appelllations effects is the the best two wines include a Clos de la Roche and a Chambertin, while the worst two wines also include one of each appellation. Overall the vintages to trump the vineyards. The group felt that 2003s were a surprise.

Return to previous page