Johan Bollen and collegues (2009) use “clickstreams” to map science interaction in their latest PLoS article. And they find in Figure 5 that “Ecology” sits in-between as a broker between social science and environmental/biological science.

The other researchers of the article are Herbert Van de Sompel, Aric Hagberg, Luis Bettencourt, Ryan Chute, Marko A. Rodrigue, and Lyudmila Balakireva.

The article is discussed further by Kelvin Kelly on his blog The Technicum

Previous maps of the relationship between branches of modern science were done by mapping the citations among journal articles. […] Instead of mapping links, [the new method by Bollen et al 2009] maps clicks. The program reads the logs of the servers offering online journals (the most popular way to get articles today) and records the clickstream of a researcher as they hop from one article to the next. Then these clickstreams (1 billion interactions in this case) are mapped to sort out the relationships generated by users. […] According to the authors of the the paper the advantages of the clickstream versus citation method is that clickstreams give you a real time picture and are broader in scope. They note that “the number of logged interactions now greatly surpasses the volume of all existing citations.”

I’ve been wondering about the future of Google and search engines in
general. […] Wouldn’t be smart to also incorporate the wisdom of crowds of people clicking on sites as well. Mining the clickstream as well as the link graph? I wondered if Google was already doing this? [which they do according to Kelvin Kelly…] The number of clicks will continue to outpace the number of links, so I expect that in the future more and more of the web’s structure will be determined by clickage rather than linkage.