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Alt i S lfi h dAltruism, Selfishness, and ContributionContribution
on the Social WebJohn Riedl
GroupLens ResearchU i it f Mi tUniversity of Minnesota
UNIVERSITY OF MINNESOTA
Messagesg
Web 2.0 is The Social WebPeople Connecting to PeopleTechnology Enabling CommunityTechnology Enabling Community
Carlson School March 20094
Google PageRankg g
Value of a page is the value of the pages p g p gthat link to itRecursive!Recursive!Fight for Attention: The Shoe Store
The Rich get Richer
Carlson School March 20098
Google Street View in UKg• My B&B in London
h // l k/ ?f & &hl &o http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=high+street+kensington&sll=51.490643,-0.158637&sspn=0.010515,0.016243&ie=UTF8&ll=51.505203,-0.193301&spn=0,359.991878&z=17&layer=c&cbll=51.505309,0.193301&spn 0,359.991878&z 17&layer c&cbll 51.505309,-0.192387&panoid=8ACFOo-EYapAmvgcuRoz_Q&cbp=12,79.63692756901483,,0,-8.672391017173075
• Link to BBC Videoo 0:00 – 2:00
• Privacy RisksPrivacy Riskso Photos of people leaving sex shopso Photos of naked toddler playing in park
Carlson School March 200914
Opportunitypp y
How can we mine free activity?f yWhat are the risks in these data?
Carlson School March 200915
Tag Selection Algorithms
“The Quest for Quality Tags”S. Sen, F. Harper, A. LaPitz, J. RiedlGROUP 2007
Carlson School March 200920
Catcher in the Rye
Huge number of tagsRQ: How can a tagging system show users tags system show users tags
they want to see?
Carlson School March 200921
Users don’t agreeMost controversial tags (Bayesian expected entropy):
tag entropy # #tag entropy # #comedy 0.987 28 30
classic 0.986 25 24
stylized 0.983 20 21
nudity (full frontal) 0.980 18 20
romance 0 980 18 17romance 0.980 18 17
quirky 0.977 25 20
magic 0.974 18 15
animation 0.974 26 20
Steven Spielberg 0.973 12 12
i fi 0 972 14 17
Carlson School March 200922
sci-fi 0.972 14 17
Tag PredictionR d b li 21%
gRandom baseline: 21%
Implicit features:number of applications (39%)number of applications (39%)number of users (51%)number of searches for a tag (44%)number of users who searched for a tag (48%)number of users who searched for a tag (48%)length of tag (42%)
Moderation-based features:global average rating for a tag (59%)user-normalized global average rating for a tag (62%)tag reputation (57%)tag reputation (57%)
Hybrid combinations: logistic regression, decision trees (67%)
Carlson School March 200923
Opportunities
How can a system distinguish between How can a system distinguish between “good” tags and “bad” tags?C f lk b d? Can folksonomy be encouraged? o Showing users more tags leads to more
b l vocabulary reuse o How much convergence is valuable?
Carlson School March 200925
The Predictive Power of Online ChatterChatter
• Gruhl, Guha, • Volume of blog Kumar, Novak, Tomkins
gpostings predict sales rank of books
• Yahoo• ACM KDD 2005
• Queries can be automatically
t d i generated in many cases.
• Can sometimes • Can sometimes predict spikes in sales rank.
Carlson School March 200931
sales rank.
Anti-aliasing on the WebJasmine Novak,
Prabhakar Prabhakar Raghavan, Andrew Tomkins Tomkins.
WWW 2004
Carlson School March 200932
Story: Finding Medical Records (Sweeney 2002)(Sweeney 2002)
Former Governer of Massachussetts!Medical DataEthnicity
Voter ListName
ZipBi thd t
EthnicityVisit DateDi i
NameAddressZip
Bi thd tBirthdateSex
DiagnosisProcedure
Date registeredParty affiliation
BirthdateSex
MedicationTotal Charge
yDate last voted
Carlson School March 200933
Total Charge
4. YouTube
Video by Amateurs?C i h iCopyright issues• Music videos• CBS agreement• CBS agreement
UNIVERSITY OF MINNESOTA
Why did Google Buy YouTube?y g y
$1,650 / 65 = $25 million / employee, / / p y$1,650 / 100 million views per day = $16$16$16 / 365 = $.04½ / view / year
b t G l l d h d id !… but Google already had videos!
The technology?The community!
Carlson School March 200939
The community!
Second Life
Virtual WorldPeople “live”, buy, and sell there$60M (US $) worth of “manufactured $60M (US $) worth of manufactured goods” sold this year
Carlson School March 200940
World of Warcraft
A different virtual worldMore focus on combat6 million subscribers6 million subscribers
Carlson School March 200942
Fayejin Funeraly j
On Tuesday of February 28th Illidan lost y ynot only a good mage, but a good person. For those who knew her, p ,Fayejin was one of the nicest people you could ever meet. On Tuesday she y ysuffered from a stroke and passed away later that night.g5:30 March 4th, Frostfire Hot Springs
Carlson School March 200943
“I hope azshira’s dad dies of a heart pattack, then at the funeral some guy runs in naked and pushes the coffin pover and runs around slapping people screaming LOL OWNED, then releases g ,a video of it”
Carlson School March 200945
Offshore to a Virtual World?
• Nick Yee @ PARC• Some radiology offshored to India• Skill in a game: RADAR expert?• Skill in a game: RADAR expert?
o Learn to detect patternsR d f to Rewards for correctness
• Wisdom of Crowds to combine results
Carlson School March 200953
Chocolate Rainb T Z dby Tay Zonday
Adam Bahner a Ph D student in Adam Bahner, a Ph.D. student in American Studies at the University of MinnesotaMinnesotaNumber 2 hottest viral video in historyo Hottest viral video of Summer 2007o Over 26 million views
Carlson School March 200956
Huberman Dynamics of Viral M k tiMarketingThe Dynamics of Viral Marketing,
ACM TWeb 2007, Leskovec et al., HP
Carlson School March 200959
Maximizing the Spread of Influence through a Social Network, David Kempe, Jon Kleinberg,
ÉÉva Tardos, KDD’03
Independent Cascade Modelpo Information diffuses over timeo Each neighbor who converts has a one-timeo Each neighbor who converts has a one time
chance to convert othersLinear Threshold ModelLinear Threshold Modelo Each node considers the preferences of all
neighborsneighborso If total weight passes threshold, a node
converts
Carlson School March 200960
converts
Video suggestion and discovery for YouTube: Taking random gg y gwalks through the view graph
Shumeet Baluja, et al., Google, WWW 2008
Carlson School March 200961
Opportunitiespp
Crowd-sourcinggGaming as Work?How do preferences propagate How do preferences propagate naturally?Wh t di t f d ?What predicts fads?How do recommenders influence propagation?
Carlson School March 200962
Heather Ann Tucci
“I just want to let everyone know j yAugust 19 2006 Joe Renner and Joe Shafer died and me and Samatha were hurt. … Both of them knew what they were getting in to. Yes it’s my fault g g ybecause I was the driver but think about how many of you did what I did.”y y
Carlson School March 200965
Story about VC lunchyHudson river picturesNYT Tweets during superbowlNYT Tweets during superbowlNBA Player who tweeted during half-ti f time of a game
Carlson School March 200966
So I once went on a movie date with a guy who thought it was sort of weird that I posted to Twitter about the movie pin mid-date. In retrospect, it probably was weird, and a bit rude, and I , ,wouldn't do it again (and no, there was no second date). But get a load of this ) gone.
Carlson School March 200968
Wikiality on MySpace
1:20 – 2:15: edit wikipedia to make truth“What if the number of elephants in pAfrica were increasing?”
UNIVERSITY OF MINNESOTA
Creating DestroyingCreating, Destroying, and Restoring Value in
Wiki diReid PriedhorskyJilin Chen Wikipedia
Group 2007Jilin ChenShyong (Tony) K. Lam pLamKatherine PancieraLoren TerveenJohn RiedlJ
UNIVERSITY OF MINNESOTA
Who contributes Wikipedia’s value?Wikipedia’s value?
User:Maveric149 3.8 million least frequent editorsfrequent editors
0.5% of value 14% of valueWales
Carlson School March 200979
Swartz
Challengesg
How can vandalism be detected?How efficient is Wikipedia?How much conflict is valuable?How much conflict is valuable?
Carlson School March 200983
Amazon (# 13)
Most Important Resource is Customers Customers “Selling to” CustomersCusto e s Se g to Custo e s
UNIVERSITY OF MINNESOTA
4Chan vs. eBaumsWorld
4Chano Google Trends Hacko Chocolate Raino Chocolate Rain
eBaumsWorldMany other hackso Many other hacks
o “copyright” fight with 4chan
Carlson School March 200990
The Internet is Serious Business
“A phrase used to remind those who voluntarily leave the house that being mocked on the Internet is, in fact, the end of the world.”- Encyclopedia Dramatica
UNIVERSITY OF MINNESOTA
The Social Cost of Cheap PseudonymsFriedman and Resnick, Journal of EconomicsFriedman and Resnick, Journal of Economics and Management Strategy, 2001
Th I f i C f M i l iThe Information Cost of Manipulation-Resistance in Recommender Systems R i k d S i ACM R S 08Resnick and Sami. ACM RecSys 08.
Carlson School March 200993
What Theory Tells Us…Collective Effort Modelo People will contribute more if:
h b l h ff hThey believe their effort is important to the groupThey like the group
Smaller is Bettero Slovic, Fischhoff, & Lichtenstein, 1980o People feel greater concern when the reference o People feel greater concern when the reference
group they’re part of grows smaller.Specificity Matters
S ll & L t i 2003o Small & Loewenstein, 2003o Specific identity of those helped is important in
drawing people’s support.
Carlson School March 200995
CommunityLab ResearchySocial science to increase contributionso Accessible to designerso Algorithms, interfaces, toolkits
GroupLens @ Minnesotao Recommender algorithms and interfaceso Recommender algorithms and interfaceso John Riedl, Joe Konstan, Loren Terveen
Bob Kraut and Sara Kiesler @ CMUBob Kraut and Sara Kiesler @ CMUo Social psychology of computer use
P l R i k d Y Ch @ Mi hiCarlson School March 200996
Paul Resnick and Yan Chen @ Michigan
VOICE 2 Screen shotNumerical values are represented
by smiliesby smilies
Who the contribution h lhelps
Value of each contribution
Carlson School March 200997
ResultsResultsSelf-report Behavioral data
Self 3.87 Self 7.2%
1: Strongly Disagree
All MovieLens 3.13
Similar Group 2.97
All MovieLens 10.2%
Similar Group 15.8%
2: Disagree3: Neutral4: Agree5: Strongly Agree
Dissimilar Group
2.94
Control 2.68
Dissimilar
Group 5.9%
Control 7.4%
Want Smilies on the regular interface?
1 2 3 4 5 0% 5% 10% 15% 20%
Probability of rating a movie
Carlson School March 200998
Opportunitiespp
How can contributors be motivated?How can social attacks be mitigated?o Mail list “unsubscribe”o Mail list unsubscribe
How does social psychology interact with defense algorithms?with defense algorithms?o Can the griefers be encouraged to give up?
f d b dCan freedoms be preserved?
Carlson School March 200999
10. Craigslist.org
Renting Apartments in NYC$10/posting: $2 5M/year$10/posting: $2.5M/yearCould generate $500M/year with ads“users haven’t asked for banner ads”
UNIVERSITY OF MINNESOTA
Messagesg
Web 2.0 is The Social WebPeople Connecting to PeopleTechnology Enabling CommunityTechnology Enabling Community
Carlson School March 2009105
Alt i S lfi h dAltruism, Selfishness, and ContributionContribution
on the Social WebJohn Riedl
GroupLens ResearchU i it f Mi tUniversity of Minnesota
UNIVERSITY OF MINNESOTA
Discussion Topicsp
What will happen with virtual ppeconomies?Why did Google buy YouTube?Why did Google buy YouTube?Broadcast -> Narrowcast -> Virtual LifeC i ht i th Di it l ACopyright in the Digital AgeGoverning Online Communities
Carlson School March 2009107
The Social Cost of Cheap PseudonymsPseudonyms
The Value of Reputation on eBay: A Controlled ExperimenteBay: A Controlled Experiment
UNIVERSITY OF MINNESOTA
W b it i li tiWeb site visualization
•Web link structure in hyperbolic space
•from T Tamara Munzner
Carlson School March 2009110
Videos for this Presentation, for KevinKevin
After (7) YouTubeMaking a Guitar in Second Life0:45 – 1:45Suzanne Vega Concert in Second LifeSuzanne Vega Concert in Second Life1:00 – 1:40World of Warcraft Video
( d )0:00 – 2:05 (entire video)After (9) WikipediaWikiality on YouTubeWikiality on YouTube1:20 – 2:15: edit wikipedia to make truth
Carlson School March 2009111