Six Degrees of Francis Bacon
Six Degrees of Francis Bacon is a large web-based project in digital scholarship devoted to research in the early modern social network centered on the English philosopher, politician, and Lord Chancellor of England Francis Bacon (1561 – 1626). The website is hosted by Carnegie Mellon Universities Libraries in Pittsburgh, Pennsylvania. The main feature of Six Degrees is a large, interactive network visualization of Bacon’s professional social connections, as well as relationships of higher degree, showing who was connected to whom, as well as the professions (lawyers, writers, philosophers, musical composers, etc.) of connected individuals. The network therefore provides an intuitive approach to studying social connections in early modern Britain. Each node of the network represents an individual connected to Francis Bacon in some way, through a direct connection or through higher degrees of separation. The edges (links), representing the connections, are colour coded as either statistically inferred or as a human contribution. The visualization can be zoomed to display different resolutions, enabling a detailed study of smaller social networks as well as broader overviews. It also contains rich content and hyperlinks. Clicking the nodes of the network visualization displays information on that person, including a timeline and hyperlinks to additional information on the individual from the Oxford Dictionary of National Biography, JSTOR, and Google. The graph can also be filtered by criteria chosen by users by clicking buttons on the bottom of the display window. The categories include “Diplomats”, “Judges”, “Benefactors of the Bodleian Library”, “Historians”, “Spies”, and “Painters”, among many others. Additionally, each individual represented by a node has their own network, which can be subsequently filtered by the categories of people connected to them. It is a collaborative project, synthesizing contributions from scholars and students worldwide who can “expand, revise, curate, and critique” it. The project is also interoperable. New contributions to the network are integrated into the network based on previously studied relationships.
The interoperability of Six Degrees is enabled through metadata. One of the ways in which metadata empowers the project is through the concept of a controlled vocabulary, an important concept in library and information science. It is an organization of words and phrases used for indexing and searching. Controlled vocabularies include both preferred and variant terms within a specified domain. They address issues of linguistic homography (in which words with identical spellings have different meanings, such as “lead” ([n] the chemical element or [v] the antonym of “follow”) and polysemy (in which words have multiple senses, such as the verb “to get”, meaning “to obtain” or “to understand”), as well as synonymous words and phrases (in which different words have the same meaning, such as “to irradiate” and “to brighten”). In contrast to natural language, controlled vocabulary is restricted to pre-defined, official terminology. In library science, controlled vocabularies consist of authorized terms, such as subject headings, that account for variations in spelling (e.g. American vs. Canadian spelling of “colour”).
Metadata were generated from the controlled vocabularies of several sources. Names recorded in the Francis Bacon database were cross-referenced with names imported from name authorities, including the Virtual Integrated Authority File (VIAF), the German Integrated Authority File (GND), the International Standard Name Identifier file (ISNI), and the Library of Congress Name Authority file (LCNAF), with additional links to the Oxford Dictionary of National Biography (Urberg, 2020). The ISNI record [isni.org] for Francis Bacon contains several names for him, some incorporating his title(s). For instance, “Bacchon, Franceso”, “Baccon, Francesco”, “Baco, Franciscus”, “Bacon, Francis Viscount Saint Alban, Baron of Verulam”, “Bacon, Francis (Viscount St. Albans)”, and “Verulamio, Franciscus (baro de)” are all listed. In fact there are 176 such names listed in different languages and scripts. The record also contains 46 “Related names”, including “Bacon, Anne Cooke”, “Heath, Douglas Denon”, and “Campanell, Tommaso”. “Titles” and “Notes” – including many Wikipedia entries in a variety of languages – are also part of the record. The metadata were subsequently processed. From this processed data, the networks were generated from Python scripts and enhanced with human expertise and supplemental knowledge (Urberg, 2020).
An important consideration in network visualizations is the graph layout. Complex graphs with many nodes and edges can become very difficult to read and to interpret, and therefore the graph must be presented in a way that is aesthetically pleasing and intuitive, and consequently, the layout of the graph, or how it is presented, becomes an important consideration. Six Degrees supports two user-selectable graph layouts for the network visualization: the Hooke layout and the concentric layout. The “Hooke” layout is a force-directed layout based on Hooke’s Law, wherein forces are assigned to nodes and edges. The endpoints of edges move towards each in a spring-like manner through simulated attractive forces, whereas repulsive forces between nodes account for node separation. In the concentric layout, nodes are arranged radially on concentric circles, which is conducive to visualizations where parent nodes have a large number of child nodes. For instance, the first-degree relations to Francis Bacon are the child nodes to the Francis Bacon parent node and are arranged radially around the centre parent node. Each first-degree relation becomes a parent node to the second-degree child nodes, which are arranged radially around the center first-degree parent nodes, etc. The reader is encouraged to view the different graph layouts for the main network visualization, as well as smaller sub-graphs, on the Six Degrees of Francis Bacon website.