The “small world” phenomenon which states that regardless of how seemingly distant two people are, they can be connected by a relatively short chain of mutual friendships. There is a game which leverages this phenomenon called Six Degrees of Kevin Bacon where players try to connect a Hollywood actor to Kevin Bacon through fewer than six co-appearances. Apparently this phenomenon of interconnectedness is not very recent, as researchers have shown by documenting and visualizing the social networks of famous early-modern Brits in the web app Six Degrees of Francis Bacon. For example, did you know that Francis Bacon and Queen Elizabeth I had five mutual connections?

The data from this project is public available and comes from a variety of primary sources. Viewers can easily contribute to the dataset by adding new people or connecting existing people with a new relationship. All that’s required is a login, and it doesn’t appear that the crowdsourced data is reviewed or vetted at all. However, manually entered edges only account for a small portion of the total connections in the graph. The system also generates “statistically inferred” edges. There is no description of how these are created on the website, and the closest thing I could find to an explanation was this github repository.
Regardless of how exactly these edges are created, I assume these are meetings that the system infers to have happened based on mutual friendships, geography, interests, etc. Each inferred edge is assigned a value of how confident the system is that these people met. There doesn’t appear to be any way to adjust the display threshold for this parameter through the user interface, but I figured out that you can do it by manually tweaking the URL. Call it hacking the digital humanities. This parameter has an enormous impact on the density of the displayed graph (see below), and I’m curious about why the researchers don’t make it easier for the user to adjust it.


The authors also provide no information on how they created the site on their about page, but some digging through the source code (which the authors do make available) shows that the frontend was made with the javascript framework Angular and the visualization with the javascript library d3. These are both fairly standard building blocks for interactive web apps, so this isn’t that surprising.
