The slides presented at Wikimedia Conference Japan (wcj2009).

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