Last week’s post on the metal collaboration network brought attention largely to the “giant component”–the largest subgraph in a network where all actors have at least one path to all other actors. In large networks, even sparse ones, giant components typically emerge and include the majority of actors in the network. While focusing on the giant component follows conventional practice while analyzing small world networks, perhaps worthwhile information can be inferred from actors outside of the giant component.
A few months ago I started listening to Tomahawk, a band described on Wikipedia as “an experimental alternative metal/alternative rock supergroup.” Beyond the quality of their music, I found myself intrigued by the musical background of their members. In addition to Tomahawk, their other bands include acclaimed groups such as Faith No More, Helmet, the Melvins, Fantômas, and the Jesus Lizard. Mike Patton alone has been affiliated with at least fifteen bands. Continue reading
As mentioned in a previous post, Alex Hanna and I had the opportunity to teach last week at the Higher School of Economic’s International Social Network Analysis Summer School in St. Petersburg. While last year’s workshop emphasized smaller social networks, this year’s workshop focused on online networks. For my part, I provided an introductory lecture to social network analysis along with four labs on the subject of R and social network analysis.
The introduction to social network analysis began with an historical overview, followed by outlining which concepts constitute a social network. The remaining portions review subjects relating to subgraphs, walks, centrality, cohesive subgroups, along with major research subjects in the field. Setting aside the substantive interest in networks, the first lab covered basic R usage, objects, and syntax. Admittedly, this material was relatively dryer, though necessary to make the most of the network analysis software in R. We followed this introduction to R with an introduction to R’s social network analysis software. This second lab introduces the class to the different network packages within R, reading data, basic measurements brought up in the introductory lecture, and visualization. The third R SNA lab was on the subject of graph-level indices, random graphs, and Conditional Uniform Graph tests. Both the second and third labs were conducted primarily using the igraph package. The fourth and final lab of the course was on the subject of exponential random graph modeling. For this lab, we walked through tests for homophily and edgewise-shared partner effects using data on both our Twitter hashtag (#SNASPb2013) as well as US political blogs.
The slides include scripts that download and read the data used within all lab examples.
I’ve hosted PDFs of all the slides on Google Drive.
Benjamin Lind and I have spent the last week and a half teaching at the Social Network Analysis Summer School at HSE-St. Petersburg. We’ve had about 30 students coming from as far as South Africa and Sweden, with all levels of skill and many different research interests, and have had the pleasure of teaching with some great instructors from around the world as well. You can read the backchannel chatter the #SNASPb2013 hashtag
I ran two labs on collecting network data from various Internet sources with Python. The first is a mashup of some of my prior workshops on collecting Twitter data via the API, and drawing network data through user mentions. The second shows how to retrieve network data by crawling blogs.
Technology-wise, it was my first time using a cloud service (Amazon EC2) and iPython Notebooks for teaching purposes. A few observations into EC2 for teaching: the t1.micro server level is not quite powerful enough to handle ~30 students running parsing of JSON or scrapy. So you’ll have to up the juice, otherwise. I found iPython Notebooks to be great, though — code highlighting and execution, LaTeX typesetting, and Markdown makes it a winner in my book.
Over the weekend I led a workshop on basic Twitter processing using Hadoop Streaming (or at least simulating Hadoop Streaming). I created three modules for it.
The first is an introduction of MapReduce that calculates word counts for text. The second is a (very) basic sentiment analysis of political tweets, and the last one is a network analysis of political tweets.
All the code for these workshops is on the site. What other kinds of analysis can/should be done with Twitter data?
Learning to use software always entails some startup cost. I recently had an exchange with one of my colleagues who is relatively new to social network analysis. He asked about my thoughts on a certain network analysis program and mentioned that “it’s easy to get lost with so many [network analysis] programs out there.” His impression is completely understandable. Social network analysis has become immensely popular in recent years. The rise in its popularity has especially been witnessed among gifted people capable of writing good software. Indeed, one Wikipedia list broadly describes about 70 social network analysis programs. Each of these programs have their strengths and weaknesses with regards to its contributions to the field. Given the wealth of options, which programs are worth the time investment to learn?
If you’re new to network analysis then I’d highly recommend learning the packages in R, perhaps supplemented by Pajek and/or Python packages. Here’s why:
I recently discovered Gary Weissman’s excellent post on Grey’s Anatomy Network of Sexual Relations and I felt inspired. For those who haven’t heard of the television show before, Grey’s Anatomy is a widely popular, award-winning prime-time medical drama airing on ABC which has received no shortage of critical acclaim. Meeting conventional medical drama expectations, the show quite regularly features members of its attractive cast “hooking up.” Or so I am told. In an effort to teach medical students some basic social network lessons, Weissman produced a network data set on the show’s sexual contacts between characters. Though I’m not particularly fond of the show and both sexual and fictional networks lie outside my research interests, Weissman’s post served as a remarkable demonstration of network analysis for pedagogical purposes.
Last month I had the wonderful opportunity to help instruct an intensive eight-day workshop on the subject of social network analysis. Affiliated with the Sociology of Education and Science Laboratory at the Higher School of Economics—Saint Petersburg, the workshop sought to recreate the atmosphere of ICPSR summer courses. This workshop was the first of its kind in Russia to offer social networks training as a summer methods course. Continue reading