The free tool enables users to create citation networks between any two Supreme Court cases. The network creates a visual map of the lines of cases that the two cases have in common. These visualizations can be saved, shared, commented on and even embedded in a blog post or website.
Citation networks are drawn to within three degrees of separation. The site explains what that means:
[I]magine a line of cases running from Case A to Case Z. If Case Z directly cites Case A, then that constitutes the 1-degree connection in the A-Z network. Now, if Case Z also cites to another case – Case Y – and Case Y in turn cites back to Case A, then Case Y forms a 2-degree connection in the A-Z network (Z->Y->A). Finally, if Case Y cites to yet another case – Case B – and Case B again cites to Case A, then Case B constitutes a 3-degree connection in the A-Z network (Z->Y->B->A). This tool automatically finds and displays all 1st, 2nd, and 3rd degree connections between any two user-specified Supreme Court cases.
The tool also uses data from the Supreme Court Database to visualize the political direction of cases — liberal or conservative — and vote counts. Links to the complete text of all opinions and links to the complete Spaeth data for a given case are also provided. (For more on this database, see my June 2015 post, The Supreme Court Database Behind Today’s New York Times Analysis.)
Every visualization also has its own page on CourtListener. That page lists the cases contained within the visualization and provides links to the Supreme Court Database. If the creator of the visualization has provided a description of what it represents, that would also be here.
For more on visualization tools in legal research, see the article I wrote for the ABA Journal: Visual law services are worth a thousand words–and big money.