Citation Data Gets Richer

This is a guest post by Matt Dahl, a Ph.D. student in political science at the University of Notre Dame.

Authorities sidebar with citation counts

Citation data is a keystone of legal research—both for understanding a particular judicial decision and for discovering similar ones. However, binary information about whether one opinion cites another can only tell us so much.

Therefore, today I’m excited to announce that CourtListener is now calculating and making available a much richer metric of inter-opinion connectedness. Today we are introducing citation depth to indicate how many times every opinion cites another.

This means that in addition to recognizing and recording “full” citation references—e.g., Bush v. Gore, 531 U.S. 98—CourtListener is now parsing and counting the following kinds of citations as well:

  • Short form citations (e.g., 531 U.S., at 99)
  • Supra citations (e.g., Bush, supra, at 100)
  • Id. citations (e.g., Id., at 101)
  • Ibid. citations (i.e., Ibid.)

Because these abbreviated citations lack the detailed information contained in a full citation, they can be tricky to count correctly. Thus, this upgrade represents a major advance in CourtListener’s citation-detection abilities, and brings us closer to feature parity with commercial legal research …

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