oozing out knowledge in human brains to the internet lada adamic school of information university of...
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Oozing out knowledge in human brains to the Internet
Lada AdamicSchool of InformationUniversity of Michigan
http://www.ladamic.com
Oozing out knowledge
Knowledge In ``Knowledge search is like oozing out knowledge in human brains to the Internet. People who know something better than others can present their know-how, skills or knowledge''
NHN CEO Chae Hwi-young
“(It is) the next generation of search… (it) is a kind of collective brain -- a searchable database of everything everyone knows. It's a culture of generosity. The fundamental belief is that everyone knows something.” -- Eckart Walther (Yahoo Research)
can we identify experts?
fragment of the Java Forum Q&A network
Zhang, Ackerman, Adamic, WWW 2007
ego-network structure of a technical forum
programming
Adamic et al., WWW 2008
network structure of a discussion forum
politics
8
Marc Smith: “This proves that marriage is more like wrestling than like programming”
Image: Eytan Bakshy
What can the network structure of Q&A forums tell us about interactions?
programming marriage wrestling
Does focusing more narrowly correlate with higher quality contribution?
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correlation between focus & % best
music
diseases and conditions
languages homework help
math
biology physics
chemistry
Yes, for technical/factual categories
Does focusing more narrowly correlate with higher quality contribution?
11
mor
e fo
cus
->hi
gher
qua
lity?
patents
papers
WikipediaQ&A
Adamic et al., First Monday 2010
persistence and quality
• even the most active users have intermittent activity• intermittency negatively correlated with quality
Nam, Ackerman, Adamic, CHI 2009
Why?
• What motivates users to answer hundreds to thousands of questions?
• From interviews of Naver (Korean Q&A site) participants– Altruism– Learning– Hobby– Business– Points
what to answer?
• filling in the blanks: users select unanswered questions• correcting others: last answer picked as best most often
Many answers you can get for free…What do you need to pay for?
TaskCN: popular Chinese Witkey site
Jiang, Adamic, Ackerman, ICWSM 2008, EC 2009
Taskcn knowledge sharing community
• Askers offer cash rewards for best “solution” to task
How virtual points & real bucks influence participation in Q&A forums
users learn to choose less competitive tasksav
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Field experiment
• Crowdsourcing: 120 translation tasks– all pay auction mechanism: participants
contribute solutions, only 1 is selected to receive payment
– price treatment: high, low– shill treatment: enter in our own solution as a
user with or without prior success
• results– monetary incentives incentivize spam
(85% are machine translations)
– higher pay yields better contributions
– shills discourage other quality contributions
Liu, Yang, Adamic, Chen
Q: can collaborative work yield better solutions than individual efforts?
– individual ideas & exploration– merging the best– e.g. Netflix prize
Q: what is the role of “community” in retaining workers?
for more info• Crowdsourcing and knowledgesharing: strategic user behavior on TaskCn
Yang, J., Adamic, L., Ackerman, M.S., EC2009• Questions in, KnowledgeIn?
Nam, K., Ackerman, M.S., Adamic, L., CHI 2009
• Competing to share expertise Yang, J., Adamic, L., Ackerman, M.S., ICWSM2008
• Examining knowledge sharing on Yahoo Answers Adamic, L., Zhang, J., Ackerman, M.S., Knowledge Sharing and Yahoo Answers: Everyone knows something, WWW’08
• ExpertiseRank algorithms and evaluations Zhang, J., Ackerman, M.S., Adamic, L., Expertise Networks in Online Communities: Structure and
Algorithms, WWW’07
Lada Adamic [email protected]://www-personal.umich.edu/~ladamic