WINETASTER ON 10/04/04 WITH 7 JUDGES AND 4 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2004 Richard E. Quandt
FLIGHT 1: Number of Judges = 7 Number of Wines = 4
Identification of the Wine: The judges' overall ranking:
Wine A is Vosne Romanee Les Brulees 2002 Engel ........ 2nd place Wine B is Nuits Saint Georges 2002 Dureuil-Janthial ........ 3rd place Wine C is Grand Echezeaux 2002 Engel ........ 1st place Wine D is Gevrey Chambertin 2002 Groffier ........ 4th place
The Judges's Rankings
Judge Wine -> A B C D Mike 3. 4. 1. 2. Ed 2. 4. 3. 1. Orley 3. 2. 1. 4. Frank 3. 1. 4. 2. Burt 1. 3. 2. 4. John 1. 3. 2. 4. Dick 4. 1. 3. 2.
Table of Votes Against Wine -> A B C D
Group Ranking -> 2 3 1 4 Votes Against -> 17 18 16 19
( 7 is the best possible, 28 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 = 0.0204
The probability that random chance could be responsible for this correlation is rather large, 0.9343. 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 -0.3162 Orley -0.3162 John -0.3162 Mike -0.7379 Ed -0.8000 Dick -0.8944 Frank -0.9487
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 C is Grand Echezeaux 2002 Engel 2. ........ 2nd place Wine A is Vosne Romanee Les Brulees 2002 Engel 3. ........ 3rd place Wine B is Nuits Saint Georges 2002 Dureuil-Janthial 4. ........ 4th place Wine D is Gevrey Chambertin 2002 Groffier We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 0.4286. The probability that this could happen by chance is 0.9343 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 1.00 for significance at the 0.05 level and must exceed 1.00 for significance at the 0.1 level Mike Ed Orley Mike 1.000 0.400 0.200 Ed 0.400 1.000 -0.800 Orley 0.200 -0.800 1.000 Frank -0.800 -0.200 -0.400 Burt 0.000 -0.200 0.400 John 0.000 -0.200 0.400 Dick -0.400 -0.400 0.000 Frank Burt John Mike -0.800 0.000 0.000 Ed -0.200 -0.200 -0.200 Orley -0.400 0.400 0.400 Frank 1.000 -0.600 -0.600 Burt -0.600 1.000 1.000 John -0.600 1.000 1.000 Dick 0.800 -0.800 -0.800 Dick Mike -0.400 Ed -0.400 Orley 0.000 Frank 0.800 Burt -0.800 John -0.800 Dick 1.000 Pairwise correlations in descending order 1.000 Burt and John Significantly positive 0.800 Frank and Dick Not significant 0.400 Mike and Ed Not significant 0.400 Orley and Burt Not significant 0.400 Orley and John Not significant 0.200 Mike and Orley Not significant 0.000 Mike and John Not significant 0.000 Orley and Dick Not significant 0.000 Mike and Burt Not significant -0.200 Ed and Frank Not significant -0.200 Ed and John Not significant -0.200 Ed and Burt Not significant -0.400 Mike and Dick Not significant -0.400 Orley and Frank Not significant -0.400 Ed and Dick Not significant -0.600 Frank and John Not significant -0.600 Frank and Burt Not significant -0.800 Mike and Frank Not significant -0.800 Ed and Orley Not significant -0.800 Burt and Dick Not significant -0.800 John and Dick Not significant
COMMENT: They were all wonderful wines and despite being very young, they were all extremely accessible and enoyable to drink. The Grand Echezeaux had the longest finish and was somewhat more tannic in style. The comparative excellence of these wines may be obscured by their youth: great Burgundies are often characterized by their ability to achieve complexity over time. The dispersion and scores of the wines is due to the fact that all the wines were very good. It is also interesting to note that the Grand Echezeaux, which was double the price of the other wines, was in effect considered an equivalent wine.
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