WINETASTER ON 5/5/97 WITH 7 JUDGES AND 7 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2011 Richard E. Quandt, V. 1.65
FLIGHT 1: Number of Judges = 7 Number of Wines = 7
Identification of the Wine: The judges' overall ranking:
Wine A is Ch. Lafite 1976 ........ 5th place Wine B is Ch. Lafite 1966 ........ 7th place Wine C is Ch. Lafite 1975 ........ 2nd place Wine D is Ch. Lafite 1989 tied for 3rd place Wine E is Ch. Lafite 1990 ........ 6th place Wine F is Ch. Lafite 1959 ........ 1st place Wine G is Ch. Lafite 1979 tied for 3rd place
The Judges's Rankings
Judge Wine -> A B C D E F G Bob 5. 1. 4. 7. 3. 2. 6. Ed 6. 7. 4. 3. 5. 1. 2. Ken 7. 6. 5. 3. 1. 4. 2. John 1. 6. 7. 2. 3. 5. 4. Burt 5. 7. 4. 2. 6. 1. 3. Orley 4. 2. 1. 5. 6. 3. 7. Dick 2. 3. 1. 6. 7. 5. 4.
Table of Votes Against Wine -> A B C D E F G
Group Ranking -> 5 7 2 3 6 1 3 Votes Against -> 30 32 26 28 31 21 28
( 7 is the best possible, 49 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 = 0.0598
The probability that random chance could be responsible for this correlation is rather large, 0.8673. 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 0.2167 Ed 0.2000 Orley -0.3784 Bob -0.3964 Ken -0.5045 Dick -0.6667 John -0.7207
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 F is Ch. Lafite 1959 2. ........ 2nd place Wine C is Ch. Lafite 1975 3. tied for 3rd place Wine D is Ch. Lafite 1989 4. tied for 3rd place Wine G is Ch. Lafite 1979 5. ........ 5th place Wine A is Ch. Lafite 1976 6. ........ 6th place Wine E is Ch. Lafite 1990 7. ........ 7th place Wine B is Ch. Lafite 1966 We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 2.5102. The probability that this could happen by chance is 0.8673 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 0.79 for significance at the 0.05 level and must exceed 0.71 for significance at the 0.1 level Bob Ed Ken Bob 1.000 -0.321 -0.250 Ed -0.321 1.000 0.500 Ken -0.250 0.500 1.000 John -0.571 -0.071 0.107 Burt -0.429 0.929 0.250 Orley 0.536 -0.286 -0.714 Dick 0.071 -0.321 -0.786 John Burt Orley Bob -0.571 -0.429 0.536 Ed -0.071 0.929 -0.286 Ken 0.107 0.250 -0.714 John 1.000 0.071 -0.643 Burt 0.071 1.000 -0.143 Orley -0.643 -0.143 1.000 Dick -0.393 -0.214 0.643 Dick Bob 0.071 Ed -0.321 Ken -0.786 John -0.393 Burt -0.214 Orley 0.643 Dick 1.000 Pairwise correlations in descending order 0.929 Ed and Burt Significantly positive 0.643 Orley and Dick Not significant 0.536 Bob and Orley Not significant 0.500 Ed and Ken Not significant 0.250 Ken and Burt Not significant 0.107 Ken and John Not significant 0.071 Bob and Dick Not significant 0.071 John and Burt Not significant -0.071 Ed and John Not significant -0.143 Burt and Orley Not significant -0.214 Burt and Dick Not significant -0.250 Bob and Ken Not significant -0.286 Ed and Orley Not significant -0.321 Bob and Ed Not significant -0.321 Ed and Dick Not significant -0.393 John and Dick Not significant -0.429 Bob and Burt Not significant -0.571 Bob and John Not significant -0.643 John and Orley Not significant -0.714 Ken and Orley Significantly negative -0.786 Ken and Dick Significantly negative
COMMENT: Burt was of the view that the 66s are not holding up well. Dick thought that the 59 is overrated, although better after 40 minutes than at the beginning. Everybody could tell the 89 and the 90 because they are younger wines. The 1975 was really good for a change. Bob felt that the diversity of views was as great as we have seen in a vertical tasting. Ed said that clearly an old wine with soft tannins and dense and rich is the best wine for currrent drinking.
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