courserank: a closed-community social site through the magnifying glass

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?