WINETASTER ON 05/04/98 WITH 7 JUDGES AND 7 WINES BASED ON RANKS, IDENT=N
Copyright (c) 1995-98 Richard E. Quandt
FLIGHT 1:
Number of Judges = 7
Number of Wines = 7
Identification of the Wine: The judges' overall ranking:
Wine A is R.Ratti Barolo Marc90 ........ 7th place
Wine B is Manzone Barolo Gram90 ........ 6th place
Wine C is A&RSeghesio BaroloVi90 ........ 4th place
Wine D is Giacosa Barolo Vill90 ........ 2nd place
Wine E is Parusso Barolo Mario90 ........ 3rd place
Wine F is P Scavino Barolo90 ........ 5th place
Wine G is Ceretto Barolo Prapo90 ........ 1st place
The Judges's Rankings
Judge Wine -> A B C D E F G
Orley 6. 5. 3. 7. 4. 2. 1.
Burt 7. 5. 4. 2. 3. 6. 1.
Frank 4. 6. 7. 2. 3. 5. 1.
Ed 5. 6. 7. 2. 4. 3. 1.
John 1. 5. 2. 4. 6. 7. 3.
Grant 7. 4. 2. 6. 5. 3. 1.
Richard 5. 3. 4. 1. 2. 6. 7.
Table of Votes Against
Wine -> A B C D E F G
Group Ranking -> 7 6 4 2 3 5 1
Votes Against -> 35 34 29 24 27 32 15
( 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 = 0.2099
The probability that random chance could be responsible for this correlation
is rather large, 0.1842. Most analysts would say that unless this
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 0.8929
Frank 0.4505
Ed 0.3784
Grant 0.1786
Orley 0.0541
Richard -0.0360
John -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 G is Ceretto Barolo Prapo90
2. ........ 2nd place Wine D is Giacosa Barolo Vill90
3. ........ 3rd place Wine E is Parusso Barolo Mario90
4. ........ 4th place Wine C is A&RSeghesio BaroloVi90
5. ........ 5th place Wine F is P Scavino Barolo90
6. ........ 6th place Wine B is Manzone Barolo Gram90
7. ........ 7th place Wine A is R.Ratti Barolo Marc90
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
Orley Burt Frank
Orley 1.000 0.214 0.000
Burt 0.214 1.000 0.643
Frank 0.000 0.643 1.000
Ed 0.214 0.571 0.893
John -0.214 -0.036 0.000
Grant 0.893 0.393 -0.107
Richard -0.750 0.179 -0.036
Ed John Grant
Orley 0.214 -0.214 0.893
Burt 0.571 -0.036 0.393
Frank 0.893 0.000 -0.107
Ed 1.000 -0.250 0.107
John -0.250 1.000 -0.107
Grant 0.107 -0.107 1.000
Richard -0.214 -0.179 -0.571
Richard
Orley -0.750
Burt 0.179
Frank -0.036
Ed -0.214
John -0.179
Grant -0.571
Richard 1.000
Pairwise correlations in descending order
0.893 Orley and Grant Significantly positive
0.893 Frank and Ed Significantly positive
0.643 Burt and Frank Not significant
0.571 Burt and Ed Not significant
0.393 Burt and Grant Not significant
0.214 Orley and Ed Not significant
0.214 Orley and Burt Not significant
0.179 Burt and Richard Not significant
0.107 Ed and Grant Not significant
0.000 Frank and John Not significant
0.000 Orley and Frank Not significant
-0.036 Burt and John Not significant
-0.036 Frank and Richard Not significant
-0.107 John and Grant Not significant
-0.107 Frank and Grant Not significant
-0.179 John and Richard Not significant
-0.214 Orley and John Not significant
-0.214 Ed and Richard Not significant
-0.250 Ed and John Not significant
-0.571 Grant and Richard Not significant
-0.750 Orley and Richard Significantly negative
COMMENT:
Comments by Orley Ashenfelter: Everyone agrees extraodrinarily good
Barolos, easy to drink today, and every sign they will improve.
Ed Bergman: Very focused wines. Rich, with ripe fruit that tends to
obscure significant tannins, making the wine luscious to drink now, but
the future will be more complex wines.
Burt Malkiel: The Ceretto was the richest and smoothest of the group.
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