SNA 101: Not just reading tea leaves

Dr Bernie Hogan [@blurky]Research Fellow, Oxford Internet Institute

University of Oxford

LocalSocialSummit, November 13, 2012

What do you already know?

Diffusion Happens

Some are influencers Science has potential

Nets look nice

Some Principles

• Influence is not an obvious process.

• Central people are not always the most popular people (but usually are)

• Visualizations can be useful, but this takes work. Sciency is bull$#!†.

Some Limits

• Estimating selection versus influence is extremely tough, even for the best.

• Visualizing more than a couple thousand points? Congrats, its now art!

• A link is not always a meaningful link

• Data cleaning is the worst part. Seriously.

Tools!• Interactive is hot! D3 and Sigma.js (or just

javascript/html5) are the future of interactive network visualization

• Gephi [Cross-Platform] creates very spiffy diagrams and has great layouts for dustballs: ForceAtlas, ForceAtlas2, YuFan Hu, FR, Nooverlap

• NodeXL [Windows] has great data management features and a couple neat visualization features. See: nodexlgraphgallery.com for inspiration.

Some networksAnd why you should care

Right and Left Wing BlogsMade with GUESSNice sharp PDF. Two blobs show clear partition.

Source: Adamic and Glance 2005

New Scientist Twitter PageMade with NodeXLShows Twitter iconsIndicates tweet diffusion and polarization

Source: ConnectedAction.net

Facebook Social NetworksMade with Sigma.js / Gephi toolkitInteractive browser-based Most nets show social roles as clusters

Source: Hogan and Melville

Facebook Global NetworkMade with R Beautiful and signifyingNote the absence of Russia, China and Africa

Source: Facebook.com

Internet Undersea CablesPackage unknownRelevance of geographyArtistic rendering shows much more

Sources: Caida, Telegeography

Obesity over timeMade with SONIAOverly clutteredBad visual variables

Networks shouldn’t look SciencySource: Christakis & Fowler. N Engl J Med 2007;357:370-9.

Two Network Demos

• Network Visualization App

• http://blogs.oii.ox.ac.uk/vis

• http://apps.facebook.com/namegencollege

• NodeXL

• http://nodexl.codeplex.com/

Network 1 Goals

• Overview

• What do clusters mean?

• Who is considered more central?

Network 2 Goals

• Is there cohesion among the group?

• Many blobs or few? Core-periphery or multi-core.

• Are certain people broadcasters?

• How can we accentuate the story?

• List people by number of tweets?

Thank YouBernie Hogan

Research Fellow, OIIhttp://people.oii.ox.ac.uk/hogan

Twitter: @blurkybernie.hogan@oii.ox.ac.uk