Had a great time today talking graph theory with a roomful of students and faculty in the humanities at the Humanities Hackathon. Here’s a (big .ppt file) link to my slides. One popular visualization was this graph of baby boys’ names from 2011, where two names are adjacent if their popularity profile across 12 representative states is very similar. (For example, names similar to “Malachi” on this measure include “Ashton” and “Kaden,” while names similar to “Patrick” include “Thomas,” “John,” “Sean,” and “Ryan.”)
The visualization is by the open-source graph-viz tool gephi.
I came home only to encounter this breathless post from the Science blog about a claim that you can use network invariants (e.g. clustering coefficient, degree distribution, correlation of degree between adjacent nodes) to distinguish factually grounded narratives like the Iliad from entirely fictional ones like Harry Potter. The paper itself is not so convincing. For instance, its argument on “assortativity,” the property that high-degree nodes tend to be adjacent to one another, goes something like this:
Real-life social networks tend to be assortative, in the sense that the number of friends I have is positively correlated with the number of friends my friends have.
The social network they write down for the Iliad isn’t assortative, so they remove all the interactions classified as “hostile,” and then it is.
The social network for Beowulf isn’t assortative, so they remove all the interactions classified as “hostile,” and then it still isn’t, so they take out Beowulf himself, and then it is, but just barely.
Conclusion: The social networks of Beowulf and the Iliad are assortative, just like real social networks.
Digital humanities can be better than this!