WINETASTER ON 12/06/10 WITH 8 JUDGES AND 9 WINES BASED ON RANKS, IDENT=N Copyright (c) 1995-2010 Richard E. Quandt, V. 1.65
FLIGHT 1: A Vertical Tasting of Vieux Château Certan
Number of Judges = 8 Number of Wines = 9
Identification of the Wine: The judges' overall ranking:
Wine A is 1993 ........ 4th place Wine B is 1990 ........ 1st place Wine C is 1989 ........ 5th place Wine D is 1966 ........ 8th place Wine E is 1952 ........ 2nd place Wine F is 1998 ........ 6th place Wine G is 1988 ........ 9th place Wine H is 1994 ........ 3rd place Wine I is 1995 ........ 7th place
The Judges's Rankings
Judge Wine -> A B C D E F G H I Ed 4. 3. 7. 9. 2. 8. 5. 1. 6. Burt 3. 7. 4. 8. 1. 6. 9. 5. 2. John 5. 3. 9. 6. 2. 1. 7. 8. 4. Mike 8. 2. 3. 5. 6. 7. 4. 1. 9. Zachy 9. 2. 3. 4. 5. 1. 8. 7. 6. Bob 2. 3. 4. 6. 1. 5. 9. 7. 8. Orley 2. 3. 1. 9. 6. 8. 7. 5. 4. Dick 4. 2. 9. 6. 3. 7. 8. 1. 5.
Table of Votes Against Wine -> A B C D E F G H I
Group Ranking -> 4 1 5 8 2 6 9 3 7 Votes Against -> 37 25 40 53 26 43 57 35 44
( 8 is the best possible, 72 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 = 0.2443
The probability that random chance could be responsible for this correlation is quite small, 0.0479. 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 Bob 0.6527 Ed 0.5439 Dick 0.4603 Burt 0.4333 Orley 0.2678 John 0.1500 Zachy 0.0000 Mike -0.0500
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 B is 1990 2. ........ 2nd place Wine E is 1952 --------------------------------------------------- 3. ........ 3rd place Wine H is 1994 4. ........ 4th place Wine A is 1993 5. ........ 5th place Wine C is 1989 6. ........ 6th place Wine F is 1998 7. ........ 7th place Wine I is 1995 --------------------------------------------------- 8. ........ 8th place Wine D is 1966 9. ........ 9th place Wine G is 1988 We now test whether the ranksums AS A WHOLE provide a significant ordering. The Friedman Chi-square value is 15.6333. The probability that this could happen by chance is 0.0479 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 0.70 for significance at the 0.05 level and must exceed 0.60 for significance at the 0.1 level Ed Burt John Ed 1.000 0.333 0.000 Burt 0.333 1.000 0.233 John 0.000 0.233 1.000 Mike 0.367 -0.467 -0.517 Zachy -0.417 -0.167 0.400 Bob 0.267 0.483 0.400 Orley 0.333 0.467 -0.300 Dick 0.783 0.283 0.250 Mike Zachy Bob Ed 0.367 -0.417 0.267 Burt -0.467 -0.167 0.483 John -0.517 0.400 0.400 Mike 1.000 0.167 -0.083 Zachy 0.167 1.000 0.233 Bob -0.083 0.233 1.000 Orley 0.100 -0.150 0.367 Dick 0.217 -0.183 0.300 Orley Dick Ed 0.333 0.783 Burt 0.467 0.283 John -0.300 0.250 Mike 0.100 0.217 Zachy -0.150 -0.183 Bob 0.367 0.300 Orley 1.000 0.117 Dick 0.117 1.000 Pairwise correlations in descending order 0.783 Ed and Dick Significantly positive 0.483 Burt and Bob Not significant 0.467 Burt and Orley Not significant 0.400 John and Bob Not significant 0.400 John and Zachy Not significant 0.367 Ed and Mike Not significant 0.367 Bob and Orley Not significant 0.333 Ed and Burt Not significant 0.333 Ed and Orley Not significant 0.300 Bob and Dick Not significant 0.283 Burt and Dick Not significant 0.267 Ed and Bob Not significant 0.250 John and Dick Not significant 0.233 Zachy and Bob Not significant 0.233 Burt and John Not significant 0.217 Mike and Dick Not significant 0.167 Mike and Zachy Not significant 0.117 Orley and Dick Not significant 0.100 Mike and Orley Not significant 0.000 Ed and John Not significant -0.083 Mike and Bob Not significant -0.150 Zachy and Orley Not significant -0.167 Burt and Zachy Not significant -0.183 Zachy and Dick Not significant -0.300 John and Orley Not significant -0.417 Ed and Zachy Not significant -0.467 Burt and Mike Not significant -0.517 John and Mike Not significant
COMMENT: All the wines reflected richness and complexity. It is also noteworthy that there was statistically significant agreement between the rankings of the tasters. An important question is this: if we had not known that there was a 46 year gap between these wines, would we have detected it? The answer is probably not. These wines are Merlot based and our present experience contradicts the conventional wisdom that Merlots are not long lived. Note that the youngest wine in this group is 12 years old. The one vintage present here that by all standards is widely considered inferior is the 1993. It was a jolly good drink. The '94 and '95 are considered mid-level in quality. They were jolly good drinks too. Parker rates the 1966 74 points, and describes it browning badly, but we did not find that at all; consequently we presume that Parker's ranking was based on a bad bottle. However, we ranked the 1966 as the second lowest wine in the group. In terms of the physical disposition of and trade dress of the wines, it is noticeable that the weight and opacity of the oldest bottle (1952) represented an earlier era versus the more modern bottle.
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