How To Shepardize in Law and AI

In common law systems such as in the US and the UK, cases which have been decided by judges (precedents) play a critical role in determinations of current, undecided cases. One of the critical reasoning principles in case based reasoning is stare decisis, which is a principle of legal conservatism — current decisions should adhere to or abide by past decisions unless specifically overturned. It is critical then to be able to identify not only what precedents bear on the current case, but also whether those precedents still represent good law, that is, legal decisions which have not been overturned. The legal researcher must search through the case base identifying those good precedents.
Shepard’s Citations is a compilation of court opinions and the relationships among the cases. To examine a current case in light of precedents is called Shepardization. An online tutorial can be found at:
How to Shepardize
An article from the journal Artificial Intelligence bearing on aspects of automated shepardization is:
Information extraction from case law and retrieval of prior cases

The Taxpayer Assets Project

In the 1990s, there was an coordinated effort by a spectrum of individuals and organisations such as Ralph Nader of the Consumer’s Union and Prof. Carole Hafner of Northeastern University to gain free access to legal information. This was called the Taxpayer Assets Project (TAP) (also referred to as the JURIS system or The Crown Jewels). An initial story is:
Taxpayer Assets Project
Two documents by Prof. Hafner on TAP:
Letter to Reno
Competition for Legal Information
And a summary of how the Clinton administration did not support the development of JURIS:
Decision not to support JURIS
Articles about recent efforts along the same lines can be found at News Media links.

Workshop on Natural Language Engineering of Legal Argumentation (NaLELA 09), June 12 2009, Barcelona, Spain

Held at the International Conference on AI and Law
June 8-12 2009, Barcelona, Spain
Workshop date: June 12, 2009
The aim of this workshop is to draw together researchers around the issues of the empirical analysis, formalisation, and implementation of legal argumentation in natural language. Such a system would be a decision-support tool which translates natural language arguments into and out of an argumentation framework or logic which supports reasoning and inference. As the interface is in natural language, the tool would be accessible to a wide range of end-users. The workshop builds on recent advances in natural language engineering and argumentation including: controlled languages, predictive editors, text mining and corpus analysis, natural language parsing, ontology construction, translation of natural language sentences into first order logic, logical inference, linguistic analysis of argumentation, and computational theories of argumentation. It draws on an interdisciplinary community in Computer Science, Linguistics, and the Law.
While argumentation can be addressed in a broad range of areas, the workshop focusses particularly on the language, logic, and computation of legal argumentation such as that found between lawyers arguing a case before a court or found in legal briefs and decisions where justifications are given for and against a decision.
For further information and submission, see NaLELA 09

Subject searches and LawCite

The World Legal Information Institute makes available on its website LawCite, which supports searches in a range of global legal databases with respect to:

  • Neutral citation
  • Parties
  • Court
  • Jurisdiction
  • Article title
  • Author
  • Year
  • Cases considered
  • Leglisation and section considered

The results are presented in a table.
Particularly interesting are extraction of parties and cases/legislation considered.
What is not clear is just how this information is indexed in the cases, whether manually or by some automated text analysis.
In addition to LawCite, WorldLII has a variety of categories among which one can search, including subjects, lawyers, parliaments.
The interesting part for me about the nature of the searches as well as the categories is that they express an informal legal ontology.

Discussion with Joe Ury of BAILLI

Yesterday, I had an interesting and informative discussion with Joe Ury, Executive Director of the British and Irish Legal Information Institute:
BAILII primarily makes legal information available over the web. The search terms are with respect to:

  • Citation
  • Case name
  • Word list (conjunctive)
  • Exact phrase (using ” “)
  • Word list (disjunctive)
  • Dates
  • Advance Query with * (morphological variants), ? (single character wildcard), Boolean operators (and, or, not), proximity operators (/n/ for n terms and near (terms less than or equal to 50 terms)
  • Unit processing with paretheses ( )
  • Jurisdiction

The results can highlight terms in the results.
By and large, these are the same sorts of search capabilities found in commerical legal case base systems.
He drew my attention to the various links for other legal institutes in the world which have a similar agenda of providing free access to the law. A world organisation links to all the available legal databases affiliated with the legal information institutes:
World Legal Information Institute
We discussed issues related to building and using the databases, for there are different issues of ownership in the different jurisdictions. Navigating these issues, addressing concerns, and adjusting to local circumstances are, apparently, a primary reason for the preeminence of commercial vendors. These issues may have to do with who claim copyright, how cases can be excluded, the role of legal professionals (from Supreme Court Justices or Law Lords, to transcribers, to councils on law reporting, to the court system, and on down to law students) in determining access. On the other hand, BAILII is funded by a wide consortium of legal professionals, which would appear to provide defacto support of distribution of legal information. This contrasts with the situation in the US, where the government assigned sole distribution of legal information to commercial vendors, and in this regard, the US has far less available publically (though see the efforts at
These observations led into a wide-ranging discussion about the role of law in civil society along with the best means to distribute legal information. There are pros and cons on every side.
Private Distribution:

  • Provide value added information such as Head Notes or Abstracts
  • Provide a high level of service
  • Allow widely distributed access
  • Have quality control and assurance
  • Preindex cases to faciliate search

Public Distribution:

  • The public’s interest and right to know the operations of the legal system which governs their lives
  • Free access (so wider distribution)
  • Support for novel searches and applications

There are the interests of a range of stakeholders:

  • Public administrations
  • Judicial and legal professionals
  • The public which is served by the application of the law
  • Private firms with significant assets

Access to the law is not unlike access to other fundamental ‘resources’ where public and private interests mingle and compete.
My own view is that the more public the discussions are about the issues, the more productive the outcome will be for all concerned. For example, private interests certainly provide value added goods and services. However, one might argue that novel private interests could grow out of access to at least basic case decisions and legislation. Allowing access to legal information could, perhaps, make the legal system more transparent and efficient, at least to the extent that this is possible. One analogy Joe and I discussed was that allowing access to medical reports to those who wanted it encouraged a greater participation on the part of those being served by the medical system. Yet, it also exposed medical professionals to greater exposure and liability. In turn, this was followed by changes in how service was delivered. Overall, the medical system adapted and improved.
One point is very clear. The movement for free access to legal information is growing. It will be interesting to see how the various stakeholders adapt, compete, and collaborate over the coming years.

Article in New York Times about Open Source Legal Information

A recent article in the New York Times about open sources of legal information in the US.
An Effort to Upgrade a Court Archive System to Free and Easy
In this article, some of the issues about legal information sources in the US are lain out — the role of the court system, private services, and emerging open services. The interesting aspect from my point of view is the observation that the open services do not provide easy search capabilities.
Adam Wyner