With the popularization of online social networks (OSNs), various software tools have been created to extract social data for research. One open-source freeware tool is NodeXL, which is a plug-in to more recent versions of Microsoft Excel (Office 2008 and 2010 on PCs, and Office 2011 on Macs).
This software tool integrates functions enabled by application programming interfaces (APIs) from Facebook, Twitter, YouTube, Flickr, and other social-media sites to enable queries of the public data sets. These offer slice-in-time views of various social networks. The data is collected in Excel (as a .xlsx file), and various graph metrics may be calculated on that raw data. Further, the data may be depicted in more than a half-dozen visualizations.
The above image illustrates a recent query done on “kstate_pres” (Kirk Schulz’s Twitter handle). This took over five hours to process (in part because Twitter pauses the query after a certain amount of information is accessed for their own server load balancing). Then outputting the graph metrics and the visualization involved more time.
The directed graph visualization that evaluated his Twitter network (two paths out) had more than 30,670 nodes (a.k.a. vertices), in a fairly dense network. The clustered visualization shows 23 clusters. The maximum geodesic distance (degrees of separation between the farthest nodes in this network) is only 3.8. The visualization used the Fruchterman-Reingold layout algorithm.
To see the entire visualization and the graph data linked to this network, go to the NodeXL Graph Gallery posting (or click the image above). The entire data set may be downloaded here. With NodeXL downloaded, one can actually mouse over each of the nodes and read the name of the individual “tweeting” and see their text message. A text analysis may also be run on the downloaded messages.
For a brief primer, visit “A Brief Overview of Social Network Analysis and NodeXL”. This presentation contains examples of the various types of node-link visualizations that are possible through NodeXL. To see one run on EDUCAUSEEditor (with her permission), see the 11,000 node-strong social network output using the Harel-Koren Fast Multiscale layout algorithm.
To download NodeXL, visit Microsoft’s CodePlex site. The source code is available for developers. This software was created under the auspices of the Social Media Research Foundation.
