WINETASTER ON 11/05/12 WITH 7 JUDGES AND 8 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2012 Richard E. Quandt, V. 1.65
FLIGHT 1: Number of Judges = 7 Number of Wines = 8
Identification of the Wine: The judges' overall ranking:
Wine A is Dominus 2002 ........ 3rd place Wine B is Chateau Montelena 2003 ........ 4th place Wine C is Dominus 1994 ........ 5th place Wine D is Chateau Montelena 1992 ........ 8th place Wine E is Chateau Montelena 2002 ........ 7th place Wine F is Dominus 2003 ........ 1st place Wine G is Dominus 1986 ........ 2nd place Wine H is Chateau Montelena 1986 ........ 6th place
The Judges's Rankings
Judge Wine -> A B C D E F G H Zaki 3. 4. 5. 8. 6. 1. 2. 7. Burt 4. 3. 5. 6. 7. 1. 2. 8. Bob 3. 2. 1. 6. 7. 5. 4. 8. Mike 3. 4. 7. 8. 6. 5. 2. 1. Frank 1. 3. 5. 8. 6. 4. 2. 7. Orley 8. 7. 3. 6. 1. 2. 4. 5. Dick 2. 4. 8. 5. 7. 3. 6. 1.
Table of Votes Against Wine -> A B C D E F G H
Group Ranking -> 3 4 5 8 7 1 2 6 Votes Against -> 24 27 34 47 40 21 22 37
( 7 is the best possible, 56 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 = 0.3042
The probability that random chance could be responsible for this correlation is quite small, 0.0372. 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 Zaki 0.9701 Frank 0.8095 Burt 0.7979 Mike 0.3333 Bob 0.1916 Dick 0.0238 Orley -0.2857
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 Dominus 2003 2. ........ 2nd place Wine G is Dominus 1986 3. ........ 3rd place Wine A is Dominus 2002 4. ........ 4th place Wine B is Chateau Montelena 2003 5. ........ 5th place Wine C is Dominus 1994 6. ........ 6th place Wine H is Chateau Montelena 1986 7. ........ 7th place Wine E is Chateau Montelena 2002 --------------------------------------------------- 8. ........ 8th place Wine D is Chateau Montelena 1992 We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 14.9048. The probability that this could happen by chance is 0.0372 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 Zaki Burt Bob Zaki 1.000 0.905 0.452 Burt 0.905 1.000 0.548 Bob 0.452 0.548 1.000 Mike 0.333 0.095 -0.167 Frank 0.833 0.714 0.619 Orley 0.095 -0.024 -0.286 Dick 0.095 0.000 -0.333 Mike Frank Orley Zaki 0.333 0.833 0.095 Burt 0.095 0.714 -0.024 Bob -0.167 0.619 -0.286 Mike 1.000 0.452 -0.286 Frank 0.452 1.000 -0.310 Orley -0.286 -0.310 1.000 Dick 0.619 0.119 -0.524 Dick Zaki 0.095 Burt 0.000 Bob -0.333 Mike 0.619 Frank 0.119 Orley -0.524 Dick 1.000 Pairwise correlations in descending order 0.905 Zaki and Burt Significantly positive 0.833 Zaki and Frank Significantly positive 0.714 Burt and Frank Significantly positive 0.619 Mike and Dick Not significant 0.619 Bob and Frank Not significant 0.548 Burt and Bob Not significant 0.452 Zaki and Bob Not significant 0.452 Mike and Frank Not significant 0.333 Zaki and Mike Not significant 0.119 Frank and Dick Not significant 0.095 Zaki and Orley Not significant 0.095 Burt and Mike Not significant 0.095 Zaki and Dick Not significant 0.000 Burt and Dick Not significant -0.024 Burt and Orley Not significant -0.167 Bob and Mike Not significant -0.286 Mike and Orley Not significant -0.286 Bob and Orley Not significant -0.310 Frank and Orley Not significant -0.333 Bob and Dick Not significant -0.524 Orley and Dick Not significant
COMMENT: The Dominus was preferred by the group both year by year and in terms of total votes against; in fact, three of the Dominus wines were ranked first, second and third respectively. Vineyard preference superseded vintage age in the preference of the group. Many people said and the data agreed that these wines were very similar. And they didn't change very much during the tasting; moreover they were of very high quality. The younger wines certainly held their own against the older.
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