# Seminar of Computer Networks: Online Social Networks

# Academic Year 2008 / 2009

Online social networks have become a major driving phenomena on the web
since the Internet has expanded as to include users and their social
systems in its description and operation. Internet has developed from a
communication medium and information sharing devise into a platform
enabling a wide range of new social activities and applications. There
is a growing number of highly-popular user-centric applications in
Internet that rely on social networks for mining and filtering
information, for providing recommendations, tags, annotations, as well
as for ranking of documents and services. Successfully striking examples
are collaborative recommendation systems (e.g., Amazon for books and
Netflix for DVDs), folksonomies - systems of collaborative social
tagging - (e.g., Citeulike, Delicious, Flickr and Youtube), cooperative
systems for building repositories of information as Wikipedia, systems
of social networking (e.g., myspace, Facebook) and forum of discussion
and opinion formation (e.g., blogs and Web communities). In this course
we will present the design principles and the main structural
properties of on-line social networks and some of the applications
that rely on the social network paradigm.
### Announcements

**17/6/2009: More details have been added about project 4.**

**18/5/2009: The second set of homeworks and the projects are out.**

**6/5/2009: The solution of the first homework are out.**

**15/4/2009: There will be a rescheduling in May. The classes of May 6, 13,
and 20 will move to Mondays May 4, 11, and 18, from 10:00-14:00. The class of
Prof. Vitaletti will move from Monday to Wednesday from 12:00-15:30 at
l'Aula Magna (1st floor).**

**1/4/2009: The first homework is out. It is due on April 29, before the class.**

You can do the homeworks in groups of 3 students or less. If you are trying to
find a group or people, send an email to Aris to try to match you.

### Instructors

Prof. Stefano Lenardi,
Sapienza University of Rome

Dr. Aris Anagnostopoulos,
Sapienza University of Rome,
email: aris@cs.brown.edu

Dr. Debora Donato, Yahoo! Reasearch Barcelona

Guest Lecturers

Prof. Jared Saia, University of New Mexico

Navin Rustagi, University of New Mexico

Prof. Guido Caldarelli, National
Research Counsil

### When and Where

**When: ** Wednesday 12.00-1.30 and 2.00-3.30

**Where: ** Via Ariosto 25, Aula B1

### Office Hours

**Aris:** Monday, 2pm-4pm, office B118. If you have classes at this time we can
arrange by email.

### Book

There does not exist a book for the class material. We will post the slides
and maybe some notes for some of the lectures.

### Syllabus

We will cover some of the following topics, and maybe a few more to be
decided:
- Structure of social networks
- Models for social networks
- Detecting communities
- Epidemics and influence processes
- Protection from viruses
- Anonymity
- Finding content in blogs
- Algorithms for graph mining
- Spam
- Reputation management

### Homeworks, Exams

We will have 3 homework sets and a final project.
You will work in groups of 3 for homeworks and for the project.

For the project you will have two options:
- An applied project, such as building a facebook application
- A litterature survey: you will choose a topic related to the class
material, you will find papers about it, you will prepare a summary of
the papers and you will give a short presentation (about 20-30 min).

Homework 1
Out: 1/4/2009 Due: 29/4/2009, before the
class. [Solutions]

Homework 2
Out: 1/4/2009 Due: 10/6/2009.

Projects

Proceedings of WWW
2008, KDD 2008, and
WWW 2008.
### Handouts

Class notes (last updated 15/4/2009)

11/3/2009: Basic combinatorics

Basic matirial for counting permutations and combinations, binomial
coefficients, etc.

11/3/2009: Introduction to probability

Here you can find a brief introduction to probability. Make sure that
you understand all the material.

11/3/2009: Random variables

This describes random variable, expectation, variance, and other related
topics. We will work mostly with discrete random variables but you
should know the basics for the continuous ones.

11/3/2009: Main distribution functions

It describes the main types of distributions. Definitely understand
Section 5.1 and you can study the rest when we do them in the class

#### Slides

4/3/2009: Lecture 1, 4/3/2009: Introduction, structural
properties, Erdos-Renyi random-graph model

16/3/2009: Lecture 2, Probability, 7/3/2009: Basic
discrete probability, random variables, expectation

1/4/2009: Byzantine Aggreement, 25/3/2009, by
Prof. Jared Saia

1/4/2009: Complex Networks, 1/4/2009,
by Prof. Guido Caldarelli

10/4/2009: Epidemics, 8/4/2009: Viruses, Models,
Influence/correlation

4/5/2009: Graph Mining, 22/4/2009

4/5/2009: Reputation Management, 29/4/2009

25/5/2009: An Introduction to Social Media

25/5/2009: Expertise and Quality in Online Social Community

25/5/2009: Taxonomies, Folksonomies and Tagging: How Social Bookmarking can improve Web search

25/5/2009: Context Search

27/5/2009: Online Communities