Post on 03-Jan-2016
description
Georgia KoutrikaBenjamin BercovitzFilip KaliszanHenry LiouHector Garcia-Molina
Stanford University
COURSERANK:
A Closed-Community Social
Site through the Magnifying
Glass
Introduction
Social sites on the Web thrive
Open - simple interactions - simple tasks
uploading, reviewing, poking, socializing …
This talk: A Closed-Community, Special-Purpose Social Site
Introduction
How does CourseRank differ from other sites?
Why is CourseRank popular?
Two things Facebook does not have
Some highlights
Outline of the Talk
Overview
Special Features
Service Evolution
Phenomena and patterns
Lessons Learned
CourseRank is …
An educational and social site for Stanford students to:An educational and social site for Stanford students to:
Evaluate courses
Browse courses, instructors, books
Plan their academic program
Interact with each other
Ask and answer questions
Evaluate courses
Browse courses, instructors, books
Plan their academic program
Interact with each other
Ask and answer questions
Overview
Course Information
Course statistics
Reviews, ratings
Overview
Course planner
Overview
Course Requirements
Overview
Explore courses
Overview
Explore courses
CourseRank in numbers
1.5 year
11,334 students
18,951 courses
85,488 ratings
2,744 text reviews
Outline of the Talk
Overview
Special Features
Service Evolution
Phenomena and patterns
Lessons Learned
CourseRank
User Interface
StudentsFaculty Staff
Course Cloud
FlexRecsKeywordSearch
PlannerReq
Tracker
Statistics
Q/A
Book Exchange
Eval
Data Access
User data Official data
Well-defined closed community1
Multiple constituencies2
Special-purpose tools3
Hybrid data4
A new class of social sites
Well-defined closed community1
Multiple constituencies2
Special-purpose tools3
Hybrid data4
Special-purpose social sites
e.g., A-Space
Examples
University social site
Scientific social site
Corporate social site
Outline of the Talk
Overview
Special Features
Service Evolution
Phenomena and patterns
Lessons Learned
0
500
1000
1500
2000
2009 2010 2011 2012
Class
Num
ber
of Stu
dents Enrolled Students CourseRank Users
Popularity
FaceBook Users1: 150,557,534
Internet Users2 : 1,596,270,108
>85% of Stanford students are CourseRank users>85% of Stanford students are CourseRank users
%9,39 of Internet Users use FaceBook
1: http://blog.facebook.com/blog.php?post=468816671302: http://www.internetworldstats.com/stats.htm
0
50000
100000
150000
200000
250000
300000
350000
March April May June July August Sept October
Acc
ess
es
Usage
Usage follows the academic cycleUsage follows the academic cycle
Less predictable peaksLess predictable peaks
e.g.,Yahoo Answers
Outline of the Talk
Overview
Special Features
Service Evolution
Phenomena and patterns
Lessons Learned
Participation inequality
More users contributeMore users contribute
20% created by intermittent, 80% by active
31% lurkers, 38% intermittent, 30% active
31%31%30%30%
38%38%
http://www.90-9-1.com/
Social sites
Community Effect
0
5
10
15
Obscure Small Medium Popular
Department Size
Ave
rage A
ctiv
ity
Community Size mattersCommunity Size matters
User Profiles
0 5 10 15 20
International RelationsScience, Technology, and
Computer ScienceMathematics
CommunicationEnglish
Urban StudiesEarth Systems Program
American StudiesHuman Biology
ChemistryMathematical and
PsychologySociology
Chemical EngineeringProduct Design
PhysicsSymbolic Systems
Biomechanical EngineeringPhilosophy
User Activity
The social phenomenon is bigger than usThe social phenomenon is bigger than us
Philosophy
Physics
Sociology
Computer Science
In social sites
Truths and Lies
I am tall and
handsome
In CourseRank
Collecting official data unofficially
Good incentives make better usersGood incentives make better users
Our misconceptions
0
1
2
3
4
5
A+ A A- B+ B B- C+ C C- D+ D
Grades
Rati
ngs
No one is perfect …No one is perfect …
Students give unbiased well-informed ratings
Outline of the Talk
Overview
Special Features
Service Evolution
Phenomena and patterns
Lessons Learned
Lessons Learned
Added-value servicesAdded-value services
High-quality dataHigh-quality data
Community feelingCommunity feeling
Meaningful incentivesMeaningful incentives
Thank you
Questions?Questions?