Fourth lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
An introduction in the world of Social Network Analysis and a view on how this may help learning networks. History, data collection and several analysis techniques are shown.
The social network is a theoretical construct useful in the social sciences to study relationships between individuals, groups, organizations, or even entire societies.
Social Network Analysis: What It Is, Why We Should Care, and What We Can Lear...Xiaohan Zeng
The advent of the social networks has completely changed our daily life. The deluge of data collected on Social Network Services (SNS) and recent developments in complex network theory have enabled many marvelous predictive analysis, which tells us many amazing stories.
Why do we often feel that "the world is so small?" Is the six-degree separation purely imagination or based on mathematical insights? Why are there just a few rockstars who enjoy extreme popularity while most of us stay unknown to the world? When science meets coffee shop knowledge, things are bound to be intriguing.
I will first briefly describe what social networks are, in the mathematical sense. Then I will introduce some ways to extract characteristics of networks, and how these analyses can explain many anecdotes in our life. Finally, I'll show an example of what we can learn from social network analysis, based on data from Groupon.
Social Network Analysis power point presentation Ratnesh Shah
Basics of social network analysis,Application and also explain interesting study done by facebook , twitter, youtube and many more social media network ,slide contains some of interesting study to get knowledge about online social network analysis.
This workshop will introduce some of the main principles and techniques of Social Network Analysis (SNA). We will use examples from organizational and social media-based networks to understand concepts such as network density, diameter, centrality measures, community detection algorithms, etc. The session will also introduce Gephi, a popular program for SNA. Gephi is a free and open-source tool that is available for both Mac and PC computers.
By the end of the session, you will develop a general understanding of what SNA is, what research questions it can help you answer, and how it can be applied to your own research. You will also learn how to use Gephi to visualize and examine networks using various layout and community detection algorithms.
Instructor’s Bio: Dr. Anatoliy Gruzd is a Canada Research Chair in Social Media Data Stewardship, Associate Professor at the Ted Rogers School of Management at Ryerson University, and Director of Research at the Social Media Lab. Anatoliy is also a Member of the Royal Society of Canada’s College of New Scholars, Artists and Scientists; a co-editor of a multidisciplinary journal on Big Data and Society; and a founding co-chair of the International Conference on Social Media and Society. His research initiatives explore how social media platforms are changing the ways in which people and organizations communicate, collaborate and disseminate information and how these changes impact the norms and structures of modern society.
An introduction in the world of Social Network Analysis and a view on how this may help learning networks. History, data collection and several analysis techniques are shown.
The social network is a theoretical construct useful in the social sciences to study relationships between individuals, groups, organizations, or even entire societies.
Social Network Analysis: What It Is, Why We Should Care, and What We Can Lear...Xiaohan Zeng
The advent of the social networks has completely changed our daily life. The deluge of data collected on Social Network Services (SNS) and recent developments in complex network theory have enabled many marvelous predictive analysis, which tells us many amazing stories.
Why do we often feel that "the world is so small?" Is the six-degree separation purely imagination or based on mathematical insights? Why are there just a few rockstars who enjoy extreme popularity while most of us stay unknown to the world? When science meets coffee shop knowledge, things are bound to be intriguing.
I will first briefly describe what social networks are, in the mathematical sense. Then I will introduce some ways to extract characteristics of networks, and how these analyses can explain many anecdotes in our life. Finally, I'll show an example of what we can learn from social network analysis, based on data from Groupon.
Social Network Analysis power point presentation Ratnesh Shah
Basics of social network analysis,Application and also explain interesting study done by facebook , twitter, youtube and many more social media network ,slide contains some of interesting study to get knowledge about online social network analysis.
This workshop will introduce some of the main principles and techniques of Social Network Analysis (SNA). We will use examples from organizational and social media-based networks to understand concepts such as network density, diameter, centrality measures, community detection algorithms, etc. The session will also introduce Gephi, a popular program for SNA. Gephi is a free and open-source tool that is available for both Mac and PC computers.
By the end of the session, you will develop a general understanding of what SNA is, what research questions it can help you answer, and how it can be applied to your own research. You will also learn how to use Gephi to visualize and examine networks using various layout and community detection algorithms.
Instructor’s Bio: Dr. Anatoliy Gruzd is a Canada Research Chair in Social Media Data Stewardship, Associate Professor at the Ted Rogers School of Management at Ryerson University, and Director of Research at the Social Media Lab. Anatoliy is also a Member of the Royal Society of Canada’s College of New Scholars, Artists and Scientists; a co-editor of a multidisciplinary journal on Big Data and Society; and a founding co-chair of the International Conference on Social Media and Society. His research initiatives explore how social media platforms are changing the ways in which people and organizations communicate, collaborate and disseminate information and how these changes impact the norms and structures of modern society.
Introduction to Computational Social Science - Lecture 1Lauri Eloranta
First lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015. (http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
A high-level overview of social network analysis using gephi with your exported Facebook friends network. See more network analysis at http://allthingsgraphed.com.
Complex Social Systems - Lecture 5 in Introduction to Computational Social Sc...Lauri Eloranta
Fifth lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Clustering Methods and Community Detection with NetworkX. A slide deck for the NTU Complexity Science Winter School.
For the accompanying iPython Notebook, visit: http://github.com/eflegara/NetStruc
Overview of online collaboration and social networking tools for the purposes of online learning, stakeholder / community engagement as well as remote work / telecommuting.
Social Network Analysis Workshop
This talk will be a workshop featuring an overview of basic theory and methods for social network analysis and an introduction to igraph. The first half of the talk will be a discussion of the concepts and the second half will feature code examples and demonstrations.
Igraph is a package in R, Python, and C++ that supports social network analysis and network data visualization.
Ian McCulloh holds joint appointments as a Parson’s Fellow in the Bloomberg School of Public health, a Senior Lecturer in the Whiting School of Engineering and a senior scientist at the Applied Physics Lab, at Johns Hopkins University. His current research is focused on strategic influence in online networks. His most recent papers have been focused on the neuroscience of persuasion and measuring influence in online social media firestorms. He is the author of “Social Network Analysis with Applications” (Wiley: 2013), “Networks Over Time” (Oxford: forthcoming) and has published 48 peer-reviewed papers, primarily in the area of social network analysis. His current applied work is focused on educating soldiers and marines in advanced methods for open source research and data science leadership.
More information about Dr. Ian McCulloh's work can be found at https://ep.jhu.edu/about-us/faculty-directory/1511-ian-mcculloh
Social Network Analysis Introduction including Data Structure Graph overview. Doug Needham
Social Network Analysis Introduction including Data Structure Graph overview. Given in Cincinnati August 18th 2015 as part of the DataSeed Meetup group.
Ethical and Legal Issues in Computational Social Science - Lecture 7 in Intro...Lauri Eloranta
Seventh lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Social Network Analysis & an Introduction to ToolsPatti Anklam
This presentation was delivered as part of an intense knowledge management curriculum. It covers the basics of network analysis and then goes into the different types of tool that support analyzing networks.
Introduction to Computational Social Science - Lecture 1Lauri Eloranta
First lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015. (http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
A high-level overview of social network analysis using gephi with your exported Facebook friends network. See more network analysis at http://allthingsgraphed.com.
Complex Social Systems - Lecture 5 in Introduction to Computational Social Sc...Lauri Eloranta
Fifth lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Clustering Methods and Community Detection with NetworkX. A slide deck for the NTU Complexity Science Winter School.
For the accompanying iPython Notebook, visit: http://github.com/eflegara/NetStruc
Overview of online collaboration and social networking tools for the purposes of online learning, stakeholder / community engagement as well as remote work / telecommuting.
Social Network Analysis Workshop
This talk will be a workshop featuring an overview of basic theory and methods for social network analysis and an introduction to igraph. The first half of the talk will be a discussion of the concepts and the second half will feature code examples and demonstrations.
Igraph is a package in R, Python, and C++ that supports social network analysis and network data visualization.
Ian McCulloh holds joint appointments as a Parson’s Fellow in the Bloomberg School of Public health, a Senior Lecturer in the Whiting School of Engineering and a senior scientist at the Applied Physics Lab, at Johns Hopkins University. His current research is focused on strategic influence in online networks. His most recent papers have been focused on the neuroscience of persuasion and measuring influence in online social media firestorms. He is the author of “Social Network Analysis with Applications” (Wiley: 2013), “Networks Over Time” (Oxford: forthcoming) and has published 48 peer-reviewed papers, primarily in the area of social network analysis. His current applied work is focused on educating soldiers and marines in advanced methods for open source research and data science leadership.
More information about Dr. Ian McCulloh's work can be found at https://ep.jhu.edu/about-us/faculty-directory/1511-ian-mcculloh
Social Network Analysis Introduction including Data Structure Graph overview. Doug Needham
Social Network Analysis Introduction including Data Structure Graph overview. Given in Cincinnati August 18th 2015 as part of the DataSeed Meetup group.
Ethical and Legal Issues in Computational Social Science - Lecture 7 in Intro...Lauri Eloranta
Seventh lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Social Network Analysis & an Introduction to ToolsPatti Anklam
This presentation was delivered as part of an intense knowledge management curriculum. It covers the basics of network analysis and then goes into the different types of tool that support analyzing networks.
Big Data and Data Mining - Lecture 3 in Introduction to Computational Social ...Lauri Eloranta
Third lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
How to conduct a social network analysis: A tool for empowering teams and wor...Jeromy Anglim
Slides and details available at: http://jeromyanglim.blogspot.com/2009/10/how-to-conduct-social-network-analysis.html
A talk on using social network analysis as a team development tool.
Che cos'è una rete sociale, come nasce, a che cosa serve, come si trasforma in una rete creativa...
Il volume di Giuseppe RIva "I social network" pubblicato dal Mulino, Bologna.
Basics of Computation and Modeling - Lecture 2 in Introduction to Computation...Lauri Eloranta
Second lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Simulation in Social Sciences - Lecture 6 in Introduction to Computational S...Lauri Eloranta
Sixth lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
A Summary of Computational Social Science - Lecture 8 in Introduction to Comp...Lauri Eloranta
Final lecture of the course CSS01: Introduction to Computational Social Science at the University of Helsinki, Spring 2015.(http://blogs.helsinki.fi/computationalsocialscience/).
Lecturer: Lauri Eloranta
Questions & Comments: https://twitter.com/laurieloranta
Social Network Analysis: applications for education researchChristian Bokhove
What is your talk about?
This seminar will illustrate various social network analysis (SNA) techniques and measures and their applications to research problems in education. These applications will be illustrated from our own research utilising a range of SNA techniques.
What are the key messages of your talk?
We will cover some of the ways in which network data can be collected and utilised with other research data to examine the relationships between network measures and other attributes of individuals and organisations, and how it can be linked to other approaches in multiple methods studies.
What are the implications for practice or research from your talk?
SNA is an approach that draws from theories of social capital to study the relational ties that exist between actors or institutions in a specific context. Such ties might include learning exchanges or advice-seeking interactions. SNA techniques allow researchers to incorporate the interdependence of participants within their research questions, whereas many traditional techniques assume our participants, and their responses to our questions, are independent of one another.
Part 1: Concepts and Cases (the language of networks, networks in organizations, case studies and key concepts)
Part 2: (Starts on #44) Mapping Organizational, Personal, and Enterprise Networks: Tools
An update to last year's Social Network Analysis Introduction and Tools...
An introductory-to-mid level to presentation to complex network analysis: network metrics, analysis of online social networks, approximated algorithms, memorization issues, storage.
An interactive presentation on social network theory and analysis. Content includes information on tie formation and social capital. Network relations are explained by using the example of The A Team. Granovetter's Strength of Weak Ties Theory (1973) is also covered and weak ties and strong ties are explained. Appropriate application of social network theory to individuals understanding how to best take advantage of social networking platforms to find jobs as well as companies taking advantage of social media platforms to find followers are introduced.
A cursory view of the psychology behind some of the most effective tactics leveraged in social media. Check out this video of Ines Peschiera giving the presentation at Startingbloc -- New York, 2010: http://www.ustream.tv/recorded/5236850
Prepared as a conference tutorial, MIC-Electrical, Athens, Greece, 5th April 2014, updated and delivered again in Beijing, China, 27 January 2015 to students from Complex Systems Group, CSRC and Dept. of Engineering Physics, Tsinghua University
In social networks, where users send messages to each other, the issue of what triggers communication between unrelated users arises: does communication between previously unrelated users depend on friend-of-a-friend type of relationships, common interests, or other factors? In this work, we study the problem of predicting directed communication
intention between two users. Link prediction is similar to communication intention in that it uses network structure for prediction. However, these two problems exhibit fundamental
differences that originate from their focus. Link prediction uses evidence to predict network structure evolution, whereas our focal point is directed communication initiation between
users who are previously not structurally connected. To address this problem, we employ topological evidence in conjunction to transactional information in order to predict communication intention. It is not intuitive whether methods that work well for
link prediction would work well in this case. In fact, we show in this work that network or content evidence, when considered separately, are not sufficiently accurate predictors. Our novel approach, which jointly considers local structural properties of users in a social network, in conjunction with their generated content, captures numerous interactions, direct and indirect, social and contextual, which have up to date been considered independently. We performed an empirical study to evaluate our method using an extracted network of directed @-messages sent between users of a corporate microblogging service, which resembles Twitter. We find that our method outperforms state of the art techniques for link prediction. Our findings have implications for a wide range of social web applications, such as contextual expert recommendation for Q&A, new friendship relationships creation, and targeted content delivery.
Network Visualization guest lecture at #DataVizQMSS at @Columbia / #SNA at PU...Denis Parra Santander
- First version was a guest lecture about Network Visualization in the class "Data Visualization" taught by Dr. Sharon Hsiao in the QMSS program at Columbia University http://www.columbia.edu/~ih2240/dataviz/index.htm
- This updated version was delivered in our class on SNA at PUC Chile in the MPGI master program.
This is a presentation I gave in a workshop on "Language, concepts, history" organized by historian Joanna Innes. It took place on Friday 4/22/16 in Somerville College, Oxford.
I was one of the only people present who was not from the humanities, so it was a rather different-than-usual audience and set of participants for me.
I drew some of these slides from other presentations to rather different audiences. I emphasized rather different parts of some of those slides, so I am not sure if the slides on their own give an accurate reflection of the difference between this presentation and some of my other ones.
I thought the presentation went rather well.
Adjusting OpenMP PageRank : SHORT REPORT / NOTESSubhajit Sahu
For massive graphs that fit in RAM, but not in GPU memory, it is possible to take
advantage of a shared memory system with multiple CPUs, each with multiple cores, to
accelerate pagerank computation. If the NUMA architecture of the system is properly taken
into account with good vertex partitioning, the speedup can be significant. To take steps in
this direction, experiments are conducted to implement pagerank in OpenMP using two
different approaches, uniform and hybrid. The uniform approach runs all primitives required
for pagerank in OpenMP mode (with multiple threads). On the other hand, the hybrid
approach runs certain primitives in sequential mode (i.e., sumAt, multiply).
Levelwise PageRank with Loop-Based Dead End Handling Strategy : SHORT REPORT ...Subhajit Sahu
Abstract — Levelwise PageRank is an alternative method of PageRank computation which decomposes the input graph into a directed acyclic block-graph of strongly connected components, and processes them in topological order, one level at a time. This enables calculation for ranks in a distributed fashion without per-iteration communication, unlike the standard method where all vertices are processed in each iteration. It however comes with a precondition of the absence of dead ends in the input graph. Here, the native non-distributed performance of Levelwise PageRank was compared against Monolithic PageRank on a CPU as well as a GPU. To ensure a fair comparison, Monolithic PageRank was also performed on a graph where vertices were split by components. Results indicate that Levelwise PageRank is about as fast as Monolithic PageRank on the CPU, but quite a bit slower on the GPU. Slowdown on the GPU is likely caused by a large submission of small workloads, and expected to be non-issue when the computation is performed on massive graphs.
Learn SQL from basic queries to Advance queriesmanishkhaire30
Dive into the world of data analysis with our comprehensive guide on mastering SQL! This presentation offers a practical approach to learning SQL, focusing on real-world applications and hands-on practice. Whether you're a beginner or looking to sharpen your skills, this guide provides the tools you need to extract, analyze, and interpret data effectively.
Key Highlights:
Foundations of SQL: Understand the basics of SQL, including data retrieval, filtering, and aggregation.
Advanced Queries: Learn to craft complex queries to uncover deep insights from your data.
Data Trends and Patterns: Discover how to identify and interpret trends and patterns in your datasets.
Practical Examples: Follow step-by-step examples to apply SQL techniques in real-world scenarios.
Actionable Insights: Gain the skills to derive actionable insights that drive informed decision-making.
Join us on this journey to enhance your data analysis capabilities and unlock the full potential of SQL. Perfect for data enthusiasts, analysts, and anyone eager to harness the power of data!
#DataAnalysis #SQL #LearningSQL #DataInsights #DataScience #Analytics
3. • PART 1: SOCIAL NETWORK ANALYSIS DEFINED
• PART 2: NETWORK & GRAPH THEORY BASICS
• PART 3: MATRIX REPRESENTATION
• PART 4: KEY MEASURES
• PART 5: SOCIAL NETWORK ANALYSIS SOFTWARE
• PART 6: SOCIAL NETWORK ANALYSIS EXAMPLES
LECTURE 4OVERVIEW
5. • “Social network analysis (SNA) is a strategy for investigating social structures
through the use of network and graph theories. It characterizes networked
structures in terms of nodes (individual actors, people, or things within the network)
and the ties or edges (relationships or interactions) that connect them. Examples of
social structures commonly visualized through social network analysis include social
media networks, friendship and acquaintance networks, kinship, disease
transmission,and sexual relationships.” (Wikipedia 2015).
• “Social Network analysis is inherently an interdisciplinary endeavor. The concept of
social network analysis developed out of propitious meeting of social theory and
application with formal mathematical, statistical, and computing methodology.”
Stanley Wasserman and Katherine Fuast 1994
• “Social network analysis is neither a theory nor methodology. Rather, it is a
perspective or paradigm. It takes as its starting point the premise that social life is
created primarily and most importantly by relations and the patterns they form.”
Alexandra Marin and Barry Wellman 2011
DEFINITIONS
SOCIALNETWORKANALYSIS=SNA
(Cioffi-Revilla 2014.)
6. • Characteristics of social networks and social networks as analogy of
some parts of the society are quite common in all major social science
fields (economics, sociology, anthropology, political science,
psychology).
• Social Network Analysis is a paradigmatic viewpoint of society: it
contains the belief, that social universe is formed of and can be modeled
with networks.
• Not just a collection of methods, but also a strong theoretical
perspective: rooted in network and graph theory (in mathematics and in
computer science) and in discrete mathematics.
SOCIALNETWORKASA
VIEWPOINT
(Cioffi-Revilla 2014.)
7. • Euler and Könisberg bridge –problem already in 1736. Provided the first
principles of graph theory.
• Most active developments in early and mid 1900s.
• Sociogram – a mathematical model of social group in the 1930s
(Jakob.L. Moreno)
• Social structure – based on network model in the 1940s (Alfred
Radcliffe-Brown)
• Matrix calculus introduced to social networks in 1940s and 1950s
• Small world –phenomena presented and demonstrated in the 1950s
and 1960s
• Dynamic networks – 1970s
• First SNA software – 1980s
LONGTRADITIONS IN
NETWORKANALYSIS
(Cioffi-Revilla 2014.)
8. 7 BRIDGES OF
KÖNIGSBERG
The city of Königsberg in Prussia was set on
both sides of the Pregel River, and included
two large islands which were connected to
each other and the mainland by seven bridges.
The problem was to find a walk through the
city that would cross each bridge once and
only once.
(Wikipedia 2015.)
10. • Nodes/Vertices = the nodes of the network, can also be viewed as entities,
actors, values, sentiments, ideas, locations, attributes etc. depending on the
network at hand
• Edges between the nodes = can also be viewed as connections, links,
associations, relations, affiliations, interactions etc. Depending on the
network at hand
• Graph is a set (aggregation) of nodes and edges forming a social networks.
Thas graph is a network.
• Formally, a a graph G is an ordered pair G = (V, E) comprising a set V of
vertices or nodes together with a set E of edges or lines, which are 2-
element subsets of V (i.e. e={u,v})
COMPONENTS OFA
NETWORK
(Cioffi-Revilla 2014.)
14. • Directed edges, , from a to b, but not from b to a
• Undirected edges, meaning, that the edge connects both ways
• Graphs (networks) containing directed edges is called directed graph
• Graphs (networks) containing undirected edges is called undirected
graph
• e.g. a graph describing a process is typically a directed graph
• e.g. a graph modeling metro map is undirected graph
DIFFERENTTYPES OF
NETWORK EDGES
(Cioffi-Revilla 2014.)
17. • Edges of a graph can have weights
• Typically these model some attribute of intensity, such as probability,
distance, time, etc.
• E.g. distance between cities
• E.g. time between metro stops
• A graph with edge weights is called a weighted graph
WEIGHTED GRAPHS
tampere
turku helsinki
178 km
166 km
162 km
18. • In a signed graph the edges of the graph contain either plus (+) or minus
(-) sign (or in some applications also 0).
• e.g. signed graphs can be used in modeling political allies/adversaries
• e.g. signed graphs can be used in modeling belief systems
SIGNED GRAPHS
party1
party2 party3
+
+
-
19. • In multigraphs two nodes maybe be connected with multiple and usually
different types of edges
• Thus, all edges are not the same, and different edges between the
nodes model different types of relationships
• Multigraphs may also contain loops depending on the application
• Many “real world” networks are multigraph networks in essence, though
typically modeled as regular graphs
• e.g. Four types of relationships between a,b & c
• e.g. Loop from a to a
MULTIGRAPHS
a
b c
(Cioffi-Revilla 2014.)
20. • “In graph theory, a path in a graph is a finite or infinite sequence of
edges which connect a sequence of vertices which, by most definitions,
are all distinct from one another. In a directed graph, a directed path is
again a sequence of edges (or arcs) which connect a sequence of
vertices, but with the added restriction that the edges all be directed in
the same direction.” (Wikipedia 2015)
• Many different types of specially named paths:
• Eulerian path (crosses each edge exactly once, as in Königsberg)
• Hamiltonian path (visits each node exactly once)
PATHS
21. • Social networks change over time
• A dynamic network N(t) is a social network whose state changes as a
function of time t.
• Dynamic networks may exhibit different kinds of behavior:
• Evolution
• Growth
• Transformation
• Decay
• Termination
• E.g. a family as a network
DYNAMIC NETWORKS
(Cioffi-Revilla 2014.)
22. • Many specific graph classes have a defined name
• Typically combines a set of features (directed, undirected, weighted) and
a certain structure
• For example
• Tree graph / Forest graph
• Complete graph
• Path graph
• Cycle graph
• Random graph
• Scale-free graph
• Many many others…
SPECIFIC CLASSES OF
GRAPHS
23. • A tree is an undirected graph in which any two vertices are connected by
exactly one path. In other words, any connected graph without simple
cycles is a tree. (Wikipedia 2015, Tree(graph theory).)
TREE GRAPH
a
b
c
d
e
f
24. • A forest is an undirected graph, all of whose connected components are
trees; in other words, the graph consists of a disjoint union of trees.
Equivalently, a forest is an undirected cycle-free graph. As special cases,
an empty graph, a single tree, and the discrete graph on a set of vertices
(that is, the graph with these vertices that has no edges), all are
examples of forests. (Wikipedia 2015, Tree(graph theory).)
FORESTGRAPH
25. • In a complete graph, each pair of vertices is joined by an edge; that is,
the graph contains all possible edges.
COMPLETE GRAPH
a
b
c
d
(Wikipedia 2015, Complete_graph.)
26. • A path graph or linear graph is a particularly simple example of a tree,
namely a tree with two or more vertices with no branches.
PATH GRAPH
a b c d
(Wikipedia 2015, Path (graph theory.)
27. • In graph theory, a cycle graph or circular graph is a graph that consists of
a single cycle, or in other words, some number of vertices connected in a
closed chain.
CYCLE GRAPH
a
b
c
d
(Wikipedia 2015, Cycle graph.)
28. • A graph where the structure of the graphs and in particular the links
between the nodes of the graph is determined by some probability
distribution or some stochastic/random process.
• Can model, for example, how people get to know new people (by
chance)
RANDOM GRAPH
(Wikipedia 2015, Random graph.)
29. • A scale-free network is a network whose degree distribution follows a
power law, at least asymptotically. That is, the fraction P(k) of nodes in
the network having k connections to other nodes goes for large values
of k as
• P(k) ~ k-γ where γ 2 < γ < 3
• Contains hub-nodes that are highly more connected than an average
node
• Examples where scale free networks can be applied
• Social networks
• Internet and WWW
• Airline networks
SCALE-FREE NETWORK
(Wikipedia 2015, Scale-free network.)
30. 1. Sampling units: which are the nodes/actors of your research
2. Relational form and content: which types of interactions and which
attributes of interaction is researched/modeled
3. Levels of analysis: at which level of the network the research is
focused on
RESEARCH DESIGN
ELEMENTS
(Knoke & Yang 2008.)
31. • Nodal level = focuses on nodal level attributes and phenomena
• Dyadic level = focuses on the pairs of nodes
• Triadic level = focuses on triplets of nodes
• N-adic level = focuses on sub-graphs of N nodes
• Network level = focuses on the whole graph and network level
phenomena
• Typically a cross-level analysis, combining all of these levels
LEVELOF SOCIAL
NETWORKANALYSIS
(Knoke & Yang 2008.)
33. • In addition to visual notation, graphs can be represented as matrices,
which are more handy for calculus
• A matrix is a rectangular array formed of rows and columns
• The items that the matrix contains are called elements and they can
contain numbers, symbols or expressions
• A matrix is defined by its size: i.e. 3x2 matrix has 3 rows and 2 columns
• An excel spread sheet is a good example of an matrix with its rows and
columns
GRAPHASAMATRIX
37. • Matrix can be used to represent all the connections (edges) in the social
network
• Thus, it is a node to node mapping of the whole graph
• Typically a connection is denoted by 1 and no connection is denoted by
0
• When social networks are mapped as adjacency matrix it can also be
called as sociomatrix
• Adjacency matrix is always a square matrix (n x n), because it has all the
nodes of the graph mapped identically to its rows and columns
• Typical way of storing, exporting and importing social network graphs (for
example in .csv files)
ADJACENCYMATRIX &
SOCIOMATRIX
(Prell 2012.)
39. • Here is an adjacency matrix representing the social network of an
organization of eight people. Draw the graph representation of the
network, based on the adjacency matrix.
ASSIGNMENT
Anna Ellen Jack Jane Harry Philip Rosa William
Anna 0 1 1 1 0 1 0 0
Ellen 1 0 1 0 0 0 0 0
Jack 1 1 0 0 0 1 0 1
Jane 1 0 0 0 1 0 1 0
Harry 0 0 0 1 0 1 1 1
Philip 1 0 1 0 1 0 0 1
Rosa 0 0 0 1 1 0 0 0
William 0 0 1 0 1 1 0 0
40. • You can also represent more information in adjacency matrix than just
binary connections
• For example weights of the connections could be represented directly in
the matrix
• You could also represent different kinds of connections with different
numbers, or just different amounts of connections between the nodes
WEIGHTEDADJACENCY
MATRICES
42. • There are many quantitative measures of graphs which tell something
about the structure of the graph
• Measures can be divided to micro and macro level
1. Node level (micro)
2. Network level (macro)
QUANTITATIVE MEASURES
OF GRAPHS
(Cioffi-Revilla 2014.)
43. • Degree of the node = How many connections does a node have
• Distance between two nodes = the minimal number of connecting edges
between two nodes
• Eccentricity = the maximum distance between a node an any other
node (how far a node is from the farthest away node)
• Eigenvector centrality = Eigenvector centrality is a measure of the
influence of a node in a network. (’~how many connections &
connections to highly connected nodes)
• Betweenness centrality = number of times a node is on the shortest
path between two other nodes.
• And many others…
NODE LEVELMEASURES
(Cioffi-Revilla 2014.)
44. • Size = number of nodes in graph
• Length = number of edges (connections) in graph
• Density = Proportion of connections in relation to all possible
connections
• Diameter = Maximum eccentricity (maximum distance between two
nodes of the graph)
• Radius = Minimum eccentricity (minimum distance between two nodes
of the graph)
• Average degree = Represents the general connectedness of the graph
• Degree skewnes = How the node degrees are distributed (i.e. is the
distribution skewed, does it follow a power law etc)
• Average eccentricity = Represents the average width of the graph
• And many others…
NETWORK LEVEL
MEASURES
(Cioffi-Revilla 2014.)
46. • Originally social network analysis used no computers (as there were
none in 1930s)
• First computer based SNA applications from 1960s onwards
• Nowadays there are many ready applications that can be used in social
network analysis: UCINET, Pajek, AutoMap, ORA, NodeXL…
• Many programming languages have also their own graph and network
analysis libraries
• R: igraph, network, sna, Rsiena, statnet
• http://badhessian.org/2012/09/seven-reasons-to-use-r-for-social-
network-analysis-and-three-reasons-against/
• Python: NetworkX,sanp.py, libsna,
COMPUTATIONALSOCIAL
NETWORKANALYSIS
47. • Social Network analysis software typically contains features such as
• Representation (import/export) of the social network as adjacency
matrix
• Graphical representation of the matrix
• Automatic key measurement calculus
• Automatic graph functions/transformations
TYPICALFEATURES
48. • Each software tool have their own strengths and weaknesses
• There are available comparisons for SNA tools to help your selection (if
the tool is not pre-specified):
• E.g.
• List of available SNA software in Wikipedia:
http://en.wikipedia.org/wiki/Social_network_analysis_software<
• A comparative study of social network analysis tools
http://wic.litislab.fr/2010/slides/Combe_WIVE10_slides.pdf
• SNA software review: http://www.activatenetworks.net/social-network-
analysis-sna-software-review/
COMPARISON OF DIFFERENT
SNASOFTWARE
50. • There are many different research applications for social network
analysis in many different fields of social sciences (economics,
sociology, anthropology, psychology…)
• Gioffi-Revilla (2014) highlights
• Human cognition and belief systems
• Decision making models
• Models of organisation
• Supply chain and process models
• International relations (diplomatic networks, global organisations)
• Global social structures: i.e. small world problem
• There are many othrer areas of research applications
RESEARCHAPPLICATIONS
51. • Tantipathananandh, C., Berger-Wolf, T., & Kempe, D. (2007). A
framework for community identification in dynamic social
networks. In Proceedings of the 13th ACM SIGKDD international
conference on Knowledge discovery and data mining (pp. 717-726).
ACM.
IDENTIFYING
COMMUNITIES
52. • Fowler, J. H., & Christakis, N. A. (2008). Dynamic spread of happiness
in a large social network: longitudinal analysis over 20 years in the
Framingham Heart Study. Bmj, 337, a2338.
HOW DOES HAPPINESS
SPREAD?
53. • Kempe, D., Kleinberg, J., & Tardos, É. (2003, August). Maximizing the
spread of influence through a social network. In Proceedings of the
ninth ACM SIGKDD international conference on Knowledge discovery
and data mining (pp. 137-146). ACM.
HOWTO INFLUENCEA
SOCIALNETWORK?
54. • Read the article: “Network Analysis in the Social Sciences”
Borgatti, S. P.; Mehra, A.; Brass, D. J.; Labianca, G. (2009). Network
Analysis in the Social Sciences. Science 13 February 2009: 323 (5916),
892-895.
• What research applications are mentioned in the article?
• What areas of social network theory are highlighted?
• What methods are there for uncovering/modeling a given social
network?
LECTUREASSIGNMENT
55. • Borgatti, S. P.; Mehra, A.; Brass, D. J.; Labianca, G. (2009). Network Analysis in the
Social Sciences. Science 13 February 2009: 323 (5916), 892-895.
• de Sola Pool, I., & Kochen, M. (1979). Contacts and influence. Social networks,
1(1), 5-51.
• Tantipathananandh, C., Berger-Wolf, T., & Kempe, D. (2007). A framework for
community identification in dynamic social networks. In Proceedings of the 13th
ACM SIGKDD international conference on Knowledge discovery and data mining (pp.
717-726). ACM.
• Kossinets, G., & Watts, D. J. (2006). Empirical analysis of an evolving social
network. Science, 311(5757), 88-90.
• Fowler, J. H., & Christakis, N. A. (2008). Dynamic spread of happiness in a large
social network: longitudinal analysis over 20 years in the Framingham Heart
Study. Bmj, 337, a2338.
• Tichy, N. M., Tushman, M. L., & Fombrun, C. (1979). Social network analysis for
organizations. Academy of management review, 4(4), 507-519.
• Kempe, D., Kleinberg, J., & Tardos, É. (2003, August). Maximizing the spread of
influence through a social network. In Proceedings of the ninth ACM SIGKDD
international conference on Knowledge discovery and data mining (pp. 137-146).
ACM.
LECTURE 4 READING
56. • Cioffi-Revilla, C. 2014. Introduction to Computational Social Science.
Springer-Verlag, London
• Knoke, D.; Yang, S. 2008. Social Network Analysis. Sage Publications,
London.
• Prell, C. 2012. Social Network Analysis. Sage Publications, London.
REFERENCES