Measuring Author Contributions to the Wikipedia

B. Thomas Adler, Luca de Alfaro, Ian Pye and Vishwanath Raman

Computer Science Dept. UC Santa Cruz, CA, USAComputer Engineering Dept. UC Santa Cruz, CA, USA

Technical Report, May 2008Presented by Wen-Yuan Zhu

Outline

• Introduction• Contribution Measures• Analysis• Conclusion

Introduction

• to choose the order of authors when citing the content

• how much work various users have performed?

• incentive

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

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

Introduction(4)

• for each page p in Wikipedia

nrrrrr ,,,,, 3210

1a 2a 3a na

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

Contribution Measures(2)

• Text longevity– only to consider adding text• so that– unfair– it fails to penalize spammers and vandals

• Text longevity with penalty

Edit Longevity

Contribution Measures

average edit quality

Contribution Measures::Edit Longevity

edit quality

Contribution Measures:: Edit Longevity:: average edit quality

]1,1[),(

),(),(),(

1

1

ii

jijijiedit rrd

rrdrrdrr

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

MDIDIrrd ji ),min(2

1),max(),(

Text longevity

Contribution Measures

text quality measure

Contribution Measures:: Text longevity

Text longevity with penalty

• anti-vandal• vandals will be reverted immediately

Contribution Measures

Edit Only and Text Only

• only quantity in Edit Longevity

• only quantity in Text longevity

Contribution Measures

P

Ap paEr

rdaEditOnlya),(

)()(.

P

Ap paEr

rtxtaTextOnlya),(

)()(.

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

Analysis

Analysis

Analysis

Analysis

compare

compare

compare

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