WINETASTER ON 10/16/95 WITH 6 JUDGES AND 6 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2011 Richard E. Quandt, V. 1.65
FLIGHT 1: Number of Judges = 6 Number of Wines = 6
Identification of the Wine: The judges' overall ranking:
Wine A is Côte Rôtie, La Landonne, 1980 ........ 3rd place Wine B is Côte-Rôtie, Brune et Blonde, 1983 ........ 6th place Wine C is Côte-Rôtie, Brune et Blonde, 1985 tied for 4th place Wine D is Côte-Rôtie, La Turque, 1985 ........ 1st place Wine E is Côte-Rôtie, Brune et Blonde, 1978 tied for 4th place Wine F is Côte-Rôtie, La Mouline, 1978 ........ 2nd place
The Judges's Rankings
Judge Wine -> A B C D E F Dick 3. 4. 5. 1. 2. 6. Ed 4. 6. 3. 2. 5. 1. Burt 4. 6. 2. 1. 3. 5. Frank 4. 6. 5. 2. 3. 1. Orley 1. 5. 2. 4. 6. 3. John 3. 6. 4. 5. 2. 1.
Table of Votes Against Wine -> A B C D E F
Group Ranking -> 3 6 4 1 4 2 Votes Against -> 19 33 21 15 21 17
( 6 is the best possible, 36 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 = 0.3175
The probability that random chance could be responsible for this correlation is quite small, 0.0899. 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 Frank 0.4928 Ed 0.4928 John 0.2029 Burt 0.2000 Orley -0.0857 Dick -0.2029
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 Côte-Rôtie, La Turque, 1985 2. ........ 2nd place Wine F is Côte-Rôtie, La Mouline, 1978 3. ........ 3rd place Wine A is Côte Rôtie, La Landonne, 1980 4. tied for 4th place Wine E is Côte-Rôtie, Brune et Blonde, 1978 5. tied for 4th place Wine C is Côte-Rôtie, Brune et Blonde, 1985 --------------------------------------------------- 6. ........ 6th place Wine B is Côte-Rôtie, Brune et Blonde, 1983 We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 9.5238. The probability that this could happen by chance is 0.0899 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 0.89 for significance at the 0.05 level and must exceed 0.83 for significance at the 0.1 level Dick Ed Burt Dick 1.000 -0.257 0.543 Ed -0.257 1.000 0.371 Burt 0.543 0.371 1.000 Frank 0.086 0.771 0.257 Orley -0.371 0.429 0.086 John -0.314 0.429 -0.086 Frank Orley John Dick 0.086 -0.371 -0.314 Ed 0.771 0.429 0.429 Burt 0.257 0.086 -0.086 Frank 1.000 -0.029 0.657 Orley -0.029 1.000 0.143 John 0.657 0.143 1.000 Pairwise correlations in descending order 0.771 Ed and Frank Not significant 0.657 Frank and John Not significant 0.543 Dick and Burt Not significant 0.429 Ed and John Not significant 0.429 Ed and Orley Not significant 0.371 Ed and Burt Not significant 0.257 Burt and Frank Not significant 0.143 Orley and John Not significant 0.086 Burt and Orley Not significant 0.086 Dick and Frank Not significant -0.029 Frank and Orley Not significant -0.086 Burt and John Not significant -0.257 Dick and Ed Not significant -0.314 Dick and John Not significant -0.371 Dick and Orley Not significant
COMMENT: This tasting of Northern Rhone wines produced fairly strong agreement in the group and it is quite obvious from the results that the wines from the individual vineyards (La Landonne, La Turque, la Mouline) were significanly preferred to those from the Côtes Brune at Blonde.
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