WINETASTER ON 03/02/21 WITH 5 JUDGES AND 7 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2021 Richard E. Quandt, V. 1.65
A Tasting of Brunello di Montalcino
FLIGHT 1: Number of Judges = 5 Number of Wines = 7
Identification of the Wine: The judges' overall ranking:
Wine A is Tenute la Fuga 1995 tied for 4th place Wine B is La Gerla Riserva gli Angeli 1999 tied for 2nd place Wine C is Frescobaldi Castelgiocondo 2004 ........ 6th place Wine D is Lisini 1997 ........ 7th place Wine E is Castello Banfi 1999 tied for 4th place Wine F is Lambardi 2006 ........ 1st place Wine G is Collosorbo 2004 tied for 2nd place
The Judges's Rankings
Judge Wine -> A B C D E F G Bob 3. 2. 6. 7. 1. 4. 5. Ed 4. 3. 1. 7. 5. 2. 6. Mike4 4. 2. 6. 7. 5. 1. 3. Zaki 2. 3. 5. 6. 7. 4. 1. Dick 7. 6. 5. 4. 2. 3. 1.
Table of Votes Against Wine -> A B C D E F G
Group Ranking -> 4 2 6 7 4 1 2 Votes Against -> 20 16 23 31 20 14 16
( 5 is the best possible, 35 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 = 0.2829
The probability that random chance could be responsible for this correlation is rather large, 0.2046. 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 Mike4 0.9009 Bob 0.1261 Ed 0.0714 Zaki 0.0546 Dick -0.3063
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 Lambardi 2006 2. tied for 2nd place Wine G is Collosorbo 2004 3. tied for 2nd place Wine B is La Gerla Riserva gli Angeli 1999 4. tied for 4th place Wine A is Tenute la Fuga 1995 5. tied for 4th place Wine E is Castello Banfi 1999 6. ........ 6th place Wine C is Frescobaldi Castelgiocondo 2004 --------------------------------------------------- 7. ........ 7th place Wine D is Lisini 1997 We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 8.4857. The probability that this could happen by chance is 0.2046 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 Mike4 Bob 1.000 0.143 0.464 Ed 0.143 1.000 0.357 Mike4 0.464 0.357 1.000 Zaki 0.000 0.036 0.571 Dick -0.071 -0.393 0.071 Zaki Dick Bob 0.000 -0.071 Ed 0.036 -0.393 Mike4 0.571 0.071 Zaki 1.000 -0.143 Dick -0.143 1.000 Pairwise correlations in descending order 0.571 Mike4 and Zaki Not significant 0.464 Bob and Mike4 Not significant 0.357 Ed and Mike4 Not significant 0.143 Bob and Ed Not significant 0.071 Mike4 and Dick Not significant 0.036 Ed and Zaki Not significant 0.000 Bob and Zaki Not significant -0.071 Bob and Dick Not significant -0.143 Zaki and Dick Not significant -0.393 Ed and Dick Not significant
COMMENT: During the tasting it seemed that the wines changed very little, an unusual occurrence. they were all food-friendly, drinkable wines. They were all mid-maturity drinkable wines. We noted that none of us was familiar with the Lambardi, our top-ranked wine. The age of the wines seemed largely unrelated to the group's preferences.
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