This document summarizes a presentation given at the 24th International Conference on Legal Knowledge and Information Systems about a tool called Legal Language Explorer. It allows users to explore linguistic patterns in large corpora of US Supreme Court decisions from 1791-2005. The tool generates n-grams from the text and allows users to search for phrases and see frequency plots over time. It also allows exporting data and accessing case lists and full text. The goal is to democratize exploration of legal language for non-programmers.

1. Legal Language Explorer
Presentation @ 24th International Conference on
Legal Knowledge and Information Systems (Jurix 2011)
daniel martin katz
michael j bommarito ii
julie seaman
adam candeub
eugene agichtein

2. Law is characterized by a
relatively small number
of highly influential
cases and jurists whose
conceptualization of law
comes to dominate

3. Most Judges and Cases
Are Quickly Forgotten

4. But A Select Few Persist ...

5. Extreme Skewing is a Typical
Feature of Legal Systems
Katz, et al (2011) Katz & Stafford (2010) Geist (2009)
American Legal Academy American Federal Judges Austrian Supreme Court
Smith (2007) Smith (2007) Post & Eisen (2000)
U.S. Supreme Court U.S. Law Reviews NY Ct of Appeals

6. innovative use of
language and
metaphor is
In Part

7. How Holmes
became “Holmes”
and how Posner
became “Posner”

8. And
how certain cases
came to dominate the
rest of the corpus

9. We Believe
The decision corpus is our
archeological record

10. We Believe
The decision corpus is our
archeological record
and that record can be
usefully explored using the
tools of computational
linguistics

11. We Want
To Democratize the Exploration
of Legal Language ...

12. We Want
To Democratize the Exploration
of Legal Language ...
to folks who are not programmers

13. We Want
To Democratize the Exploration
of Legal Language ...
to folks who are not programmers
to folks who are not
technically inclined

14. We Develop a Simple Web
Interface that Leverages
the Visual Cortex

15. Relies on Our Ability
to Engage in
Pattern Detection

16. To Explore Linguistic
Patterns in Large
Corpora of Legal
Documents

17. We Start with the Full Text
Corpus of Decisions of the
United States Supreme Court
1791-2005

18. Develop a N-Gram Based Explorer
with a Portal to the Full Text, etc.

19. From Text to N-Grams...

20. Generate the N-Gram Mapping
(1) extract the opinion text from each
case and store it as a sequence of
characters
(2) convert this sequence of characters
into a sequence of words through Word
Tokenization (Penn Tree Bank Algorithm)
(3) iterate over words in the length M
sequence from index 1 to index M + 1 – N

21. Generate the N-Gram Mapping

22. Legal Language Explorer:
A Brief Tour of The Interface

23. Go to
LegalLanguageExplorer.com
And Access This Interface

24. Notice The Default Search Is
Interstate Commerce, Railroad, Deed

25. Notice The Default Search Is
Interstate Commerce, Railroad, Deed

26. For Each Comma Separated Phrase
The Frequency Plot Appears Below

27. For Each Comma Separated Phrase
The Frequency Plot Appears Below

28. Currently Supporting Every U.S. Supreme
Court Decision From 1791 - 2005

29. Currently Supporting Every U.S. Supreme
Court Decision From 1791 - 2005

30. Years Can Be Changed
By The End User

31. Years Can Be Changed
By The End User

32. Click Here to Access Various
Advanced Search Features

33. The Advanced
Search Features

34. Are the Observed Trends
a Function of changes in the
volume of the case docket?

35. Normalization allows End
User to control for the
Size of the Case Docket

36. Normalization allows End
User to control for the
Size of the Case Docket

37. Change the Graph Type
By Clicking Here

38. An Alternative Presentation
of the Data

39. Export the
Chart Data
(If You Want to Replot in
Stata, Excel, R, etc.)

40. Export the
Chart Data
(If You Want to Replot in
Stata, Excel, R, etc.)

41. The Results
(If You Want to Replot in
Stata, Excel, R, etc.)

42. Access a Case List and
Full Text Results

43. Here are the
Returned
Results

44. Download
List in
Excel
(or any .csv)

45. Download
List in
Excel
(or any .csv)

46. Access the
Full Text a
Particular
Case

47. Click Through
to Access
Results from
BulkResource.org

48. For More Information -
Full Version of the Paper
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1971953

49. For
Implementation
Details
(Including the Key Value
Storage Method, etc.)
http://www.michaelbommarito.com/
blog/2011/12/16/building-legal-
language-explorer-interactivity-
and-drill-down-nosql-and-sql/

50. Slides will Be Posted to CLS Blog
http://computationallegalstudies.com/

51. This is Only The Beginning
Stay Tuned for More in 2012
:)
daniel martin katz
michael j bommarito ii
julie seaman
adam candeub
eugene agichtein