1. The document discusses Wikipedia and analyzes data related to editor contributions and page views over time. 2. It finds that most edits on Wikipedia are made by a small group of elite editors, with 20% of editors contributing 80% of edits, following a Zipfian distribution. 3. The analysis also examines how reducing the number of editors impacts the amount of content on Wikipedia pages and determines that credible editors who make high quality contributions can help offset reductions in editor numbers.

1. Wikipedia
○
2009 11 22
1

2. 7000.00
6000.00
5000.00
4000.00
3000.00
2000.00
1000.00
0
1
2

3. ✤ Wikipedia
✤
✤
✤
✤
✤
3

4. Credibility Degree 0.4
4

5. Wikipedia
5

6. Wikipedia
5

7. Adler et al. WikiSym ’08, WWW 2007
✤
Author A
✤
Author B
✤
Author C
Lifetime = lifetime
6

8. Lifetime
50
= OK
37.5
= NG
25
12.5
0
1 2 3 4 5 6 7 8 9 10
7

9. ✤
60 =1 =167 =7 =1
✤ Wikipedia : 60
✤ 950,548 , 300 GB
✤ Wikipedian : 70
✤ : 1 11,625
8

10. ✤ (kBytes)
3,000
2,250
✤ 80% 20%
(Ziph ) 1,500
✤ 20% 750
80%
0
ID
9

11. ✤
✤
10 (x 1000 editors)
✤
9
8
7
✤
Number of Editors
6
Adler Uncredible editors
5
4
Credible editors
3
2
1
0
-10 -8 -6 -4 -2 0 2 4 6 8 10
(degrees)
Reliability Degree
? 10

12. 1.
2.
3.
4.
11

13. 1.
2.
3.
4.
?
12

14. 1.
2.
3.
4. = x -log
?
13

15. 1
0.9
0.8
1 a
2 b
Spearman's rank correlation coefficient
0.7
3 c
4 d
0.6
5 e
0.5
0.4
Amount of description
0.3
Number of articles
0.2
0.1
Amount of desciption
and Number of articles
1 b
0
2 c
0 10 20 30 40 50 60 70 80 90 100
3 a
4 e
Reduction ratio of editors (%)
5 d 14

16. ✤
✤
✤
✤
✤
✤
15

17. ✤
✤ Wikipedia
✤ 85,028 13.6%) 705,713 (Bot )
✤
✤ 98 443 )
16

18. 1,000,000
900,000
800,000
700,000
Calculation time (ms)
600,000
500,000
400,000
Amount of description
300,000
Number of articles
200,000
Amount of description and
100,000 number of articles
0
0 10 20 30 40 50 60 70 80 90 100
Decreasing ratio of editors (%)
17

19. 10
9
8 40%
7 Amount of description
Averaging Increaced Rank
and number of articles
6
Amount of description
5
4
3
2
Number of articles
1
0
Important Editor Identification Method
18

20. ✤
✤
✤
✤ 2%
✤
✤
✤
19

21. ✤
✤
✤
✤
✤
✤
20

22. 21