Special Report

Statistical Analysis

Ontario, Canada - Michael C. Williams, Corkscrew Correspondent at Large, has prepared the following document for the Virtual Corkscrew Museum & The Daily Screw:

Corkscrew Collectors On-Line

Statistical Analysis

1. Country of residence?

A total of 366 collectors identified their country of residence (90.8% of the total sample of 403). The ten countries with the most collectors registered on-line are: the USA (52.1%), the U.K. (8.9%), Australia (4.7%), Canada (4.2%), France (3.0%), Belgium (2.7%), Germany (2.5%), Sweden (2.0%), the Netherlands (1.7%), and Italy (1.7%).

	Frequency	Percent	Valid Percent	Cumulative %
No Response	37	9.2	9.2	9.2
Argentina	1	0.2	0.2	9.4
Australia	19	4.7	4.7	14.1
Austria	1	0.2	0.2	14.4
Bahrain	1	0.2	0.2	14.6
Belgium	11	2.7	2.7	17.4
Canada	17	4.2	4.2	21.6
Denmark	3	0.7	0.7	22.3
France	12	3	3	25.3
Germany	10	2.5	2.5	27.8
Hong Kong	1	0.2	0.2	28
Israel	4	1	1	29
Italy	7	1.7	1.7	30.8
Japan	2	0.5	0.5	31.3
Netherlands	7	1.7	1.7	33
New Zealand	3	0.7	0.7	33.7
Norway	1	0.2	0.2	34
Puerto Rico	1	0.2	0.2	34.2
Scotland	1	0.2	0.2	34.5
South Africa	1	0.2	0.2	34.7
Spain	3	0.7	0.7	35.5
Sweden	8	2	2	37.5
Switzerland	5	1.2	1.2	38.7
Taiwan	1	0.2	0.2	39
U.K.	36	8.9	8.9	47.9
USA	210	52.1	52.1	100
Total	403	100	100

2. In what year did you first begin collecting corkscrews?

A total of 299 collectors provided the year they began their collection (74.2% of the total sample of 403). The earliest date indicated for starting a corkscrew collection was 1935 (one respondent). The latest date indicated was 2003 (five respondents). The arithmetic average (mean) year when collections were begun was approximately 1990 (1989.84). The year that separates the top and bottom 50% of collectors (the median) was 1992 (there are as many collectors who began earlier than this date as there are those who began later). Finally, the most often reported year when corkscrew collecting began (the mode) was 1990, representing 29 respondents.

Min: 1935

Max: 2003

Mean: 1989.84

Median: 1992

Mode: 1990

For those of you who are interested in seeing your approximate percentile rank among the "early adopters" of corkscrew collecting, you may refer to the table below. For example, those who began their collections on or after 1999 are at or below the 10th percentile among on-line collectors (10% - or fewer - collectors began their quest later than this date, and 90% began their quest earlier). Similarly, those who began their collections on or before 1976 are at or above the 90th percentile (90% of corkscrew collectors began their quest later than this date, and only 10% began the hunt earlier).

Percentiles	Dates
10th	1999
20th	1998
30th	1996
40th	1995
50th	1992
60th	1990
70th	1987
80th	1984
90th	1976

3. How many corkscrews are currently in your collection?

A total of 279 collectors provided information on the number of corkscrews in their collection (69.2% of the total sample of 403). The smallest number of corkscrews indicated comprising a collection was one (five respondents). The largest number of corkscrews indicated was 5,800 (one respondent). The arithmetic average (mean) number of corkscrews in the collections of on-line respondents was approximately 375 (374.85). The number of corkscrews that separates the top and bottom 50% of collectors (the median) was 150 (there are as many collectors who have fewer corkscrews than this number as there are those who have more). Finally, the most often reported number of corkscrews in a collection (the mode) was 100, representing 20 respondents. The large difference between the mean, median and mode indicates the power of outlying scores (e.g., the collectors with one corkscrew and the collector with 5,800). The most accurate indicator of "central tendency" related to the number of corkscrews in collections is likely to be the median.

Min: 1

Max: 5,800

Mean: 374.85

Median: 150

Mode: 100

For those of you who are interested in seeing your approximate percentile rank among the number of corkscrews collected, you may refer to the table below. For example, those whose collections comprise 15 or fewer corkscrews are at or below the 10th percentile among on-line collectors (10% or fewer collectors have this number of corkscrews, and 90% have more corkscrews). Similarly, those whose collections number 1,000 or more corkscrews are at or above the 90th percentile (90% of collectors have fewer corkscrews than this, and only 10% have more).

Percentiles	Corkscrews
10th	15
20th	30
30th	70
40th	100
50th	150
60th	215
70th	350
80th	500
90th	1000

Some mysteries remain, as many respondents did not indicate the number of corkscrews comprising their collection (including one respondent who cryptically indicated, "a lot").

4. What are your three most wanted corkscrews?

Data for this variable have been based on responses to three separate inquiries regarding respondents first, second, and third most wanted corkscrew. Responses to all three questions were compiled to determine the most wanted list (i.e., each time a corkscrew was nominated as either first, second, or third most wanted, it received one vote). Many respondents identified specific individual corkscrews, while others referred to broad types of corkscrews in which they specialize (e.g., "barscrews"). A total of 170 collectors identified one or more "most wanted" corkscrews (42.2% of the total sample of 403). The corkscrews with the most "votes" appear in the table below.

Corkscrew	Votes
Thomason	15
Hootch Owl	12
Legs	11
Royal Club	9
Coffee Grinder	7
Syroco figurals	6
Woodman	5
U-Neek	5
Barscrews	5
Figurals	4

Editor: Michael, Thank you for this interesting study.

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