1. Measuring Author Contributions to the Wikipedia B. Thomas Adler, Luca de Alfaro, Ian Pye and Vishwanath Raman Computer Science Dept. UC Santa Cruz, CA, USA Computer Engineering Dept. UC Santa Cruz, CA, USA Technical Report, May 2008 Presented by Wen-Yuan Zhu

2. Outline Introduction Contribution Measures Analysis Conclusion

3. Introduction to choose the order of authors when citing the content how much work various users have performed? incentive

4. Introduction(2) previous works – the total text created – total number of edits performed but they are vulnerable to manipulation – doing a small modification – adding insignificance content

5. Introduction(3) not only quantity, but also quality – how many edits, how much text -> quantity – how long the change lasts -> quality it cannot be easily gamed

6. Introduction(4) for each page p in Wikipedia

7. Contribution Measures if your edit is longevity, then you have the higher contribution – Edit Longevity if text that you introduced is longevity, then you have the higher contribution – Text Longevity

8. Contribution Measures(2) Text longevity – only to consider adding text so that – unfair – it fails to penalize spammers and vandals Text longevity with penalty

9. Edit Longevity Contribution Measures

10. average edit quality Contribution Measures::Edit Longevity

11. edit quality Contribution Measures:: Edit Longevity:: average edit quality

12. edit distance every word that is inserted or removed contributes 1 to the distance every word that is replaced contribute 1/2 Contribution Measures:: Edit Longevity

13. Text longevity Contribution Measures

14. text quality measure Contribution Measures:: Text longevity

15. Text longevity with penalty anti-vandal vandals will be reverted immediately Contribution Measures

16. Edit Only and Text Only only quantity in Edit Longevity only quantity in Text longevity Contribution Measures

17. Analysis main namespace article revisions from the Wikipedia dump of February 6, 2007 we consider only versions before October 1, 2006 keeping only the last of consecutive versions by the same author Analysis

22. compare

25. Conclusion to present and compare several possible ways to measure author contribution to make sure that authors who make bad contributions get a low score the Edit Longevity measure is a very interesting measure in our opinion