Social Network Analysis
CUELC
of 45000 (50000+) Schools:
A Case Study of Technology
Enhanced Learning in Europe
Ruth Breuer, Ralf Klamma, Yiwei Cao, Riina Vuorikari
EC-TEL 2009, Nice, France, October 1, 2009
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-1

Social Network Analysis
Contributions to EC-TEL so far
 2006 - Klamma, Spaniol, Cao, Jarke: Pattern-Based Cross Media
CUELC Social Network Analysis for Technology Enhanced Learning in Europe
– Media Bases as research tools for TEL
– SNA as research methodology for TEL
 2007 – Programme Chair 
 2008 - Petrushyna, Klamma: No Guru, No Method, No Teacher: Self-
Oberservation and Self-Modelling of E-Learning Communities
– In-depth Analysis of a Media Base for TEL
– Combination of SNA and content-based measures
 2009 - Breuer, Klamma, Cao, Vuorikari: Social Network Analysis of
45000 Schools: A Case Study of TEL in Europe
– eTwinning database of European cooperation between schools
Lehrstuhl Informatik 5 – SNA as a tool for teachers
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-2
– Visualization and Usability

Agenda
 Social Network Analysis – Tools for teachers?
CUELC
 eTwinng Scenario and teacher-oriented SNA tool
– Data Management
– Data Analysis
– Data Visualization
– Comparision of tool use
 Conclusions & Outlook
 TeLLNet project
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-3

Social Network Analysis
and Visualization
 Social Network Analysis (SNA) [Freeman 1979,
CUELC Wasserman and Faust 1994]
- Fundamentals of Graph Theory: Size, order, radius, diameter, distances
- Bottom-up approach: Searching more complex structures
- Structural aspects: Subgraphs, k-cliques, k-plexes, cut points, bridges, clus-
tering (coefficients), connectivity, cohesion
- Special phenomena: Small-world effect, Pareto distribution
- Centralities: Degree, Closeness and Betweenness centrality
C D (u ) = d (u ) σ (u )
CC (u ) =
1
C B (u ) = ∑ st
∑ d (u, v )
v ∈V
s , t ≠ u σ st
 Network Visualization [Brandes and Wagner 2004,
Krempel 2005]
Lehrstuhl Informatik 5
- The goal is to communicate complex information intuitively
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-4
- Human perception sets limits to distinguish colors and shapes

Social Networks and Tools
 Most popular social networks realize only few analysis aspects
CUELC
 Analysis and visualization tools are not sufficient or too complex
Network Workbench Visone [Brandes and Wagner 2004]
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-5

eTwinning Scenario
eTwinning:
CUELC • Founded in 2005 and
coordinated by the
European Schoolnet
• Projects must be done
by two or more partners
from different countries
• Internet platform with
workspaces and (com-
munication) tools
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-6

Data Management for the Case Study
CUELC
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-7

Data Preprocessing
 Amount of available information:
– 40450 schools, 45217 teachers, 8361 projects
CUELC – not all attributes are required or should be aggregated
– many data records contain uncertain or wrong information
 A new relational database with tables for:
– schools, teachers, projects and countries
– affiliation between teachers – schools
– affiliation between teachers/schools – projects
Noise in data records
100,00%
45,12% 46,15%
14,10%
10,44%
10,00%
3,89%
impossible numbers
of pupils
1,00% impossible ages
unexpected values
blank values
0,10% 0,08%
0,05%
Lehrstuhl Informatik 5 0,01%
(Informationssysteme) 0,01%
Prof. Dr. M. Jarke
I5-RK-0909-8
Schools Projects Teachers 8

Statistical and Analytic Functions
 Statistical information from the database
 Already interpreted questions create networks on
CUELC demand, reduced to
- “Answer-“nodes and all nodes
on shortest paths in-between
- Direct neighbours
- Edges are automatically deleted,
if end points are removed
 SNA aspects can be applied to the current network
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-9

Speed of growth
 The teacher network grows much more than the school network
 The country network is nearly completely connected
CUELC
Network growing Network growing
by registration of schools by registration of teachers
10000 16000
9129
9000
8616 14000 13469
8000
12000
7000 10945
6000 10000 9724
5000 8000
6411
4000
6000
3000
4000
2000 1848
1746 1814 2771
2207 2560
1000 2000
110 45 518
0 0 0
2005 2006 2007 2008 2005 2006 2007 2008
new nodes total edges new nodes total edges
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-10

Visual Analytics, e.g. for
the Teacher Network of 2008
CUELC
75 % of nodes are not connected
Labels and dates help to identify complete substructures
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-11

Analysis of Subnetworks
 22 complete substructures
 Largest component with 65 nodes, 213 edges
CUELC
 Diameter 10, radius 5
 12 cut points and 4 bridges
 Clustering coefficient 0,81
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-12

Usage in the Evaluation
 Evaluation with
CUELC – German teachers who
participate in eTwinning
– “Web Science” students
from RWTH Aachen
University
 Teachers were
Positively rated Negatively rated
– Fewer
– But used the tool more
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-13

Prior Knowledge and Handling
CUELC
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-14

Impressions of
Visualization and Statistics
CUELC
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-15

Knowledge and its Application
CUELC
Teachers do not get it!
Lehrstuhl Informatik 5
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-16

Conclusions
 SNA & visualization as tools for competence
CUELC
development for teachers in learning networks
 eTwinning case study
– Complex data management issues
– Visual complexity of networks
– Experimenting with web-based tools
– Evaluation demonstrated
– Usefulness of the tool and the approach
– Need for teacher training in theory and practice
Lehrstuhl Informatik 5
– Study effect of interventions by training
(Informationssysteme)
Prof. Dr. M. Jarke in the eTwinning database
I5-RK-0909-17

Outlook: TeLLNet Project
Teachers' Lifelong Learning Networks
 Project within the EU Lifelong Learning Programme
CUELC
 3 years duration
 Project idea: Competence development for teachers in
learning networks with social network analysis and scenario
building based on eTwinning
 Partners
– European Schoolnet
– Institute for Prospective Tecnological Studies (IPTS) –
Joint Research Centre of the European Comission
– Open University of the Netherlands
Lehrstuhl Informatik 5
– RWTH Aachen University
(Informationssysteme)
Prof. Dr. M. Jarke
I5-RK-0909-18