Law as a Seamless Web? Part II

Semantic Network
In our paper Law as a Seamless Web, we offer a first-order method to generate case-to-case and opinionunit-to-opinionunit semantic networks. As constructed in the figure above, nodes represent cases decided between 1791-1865 while edges are drawn when two cases possess a certain threshold of semantic similarity. Except for the definition of edges, the process of constructing the semantic graph is identical to that of the citation graph we offered in the prior post. While computer science/computational linguistics offers a variety of possible semantic similarity measures, we choose to employ a commonly used measure. Here a description from the paper:

“Semantic similarity measures are the focus of significant work in computational linguistics. Given the scope of the dataset, we have chosen a first-order method for calculating similarity.  After lemmatizing the text of the case with WordNet, we store the nouns with the top N frequencies for each case or opinion unit. We define the similarity between two cases or opinion units A and B as the percentage of words that are shared between the top words of A and top words of B.

An edge exists between A and B in the set of edges  if  σ (A,B) exceeds some threshold.  This threshold is the minimum similarity necessary for the graph to represent the presence of a semantic connection.”  

As this a technical paper, it is slanted toward demonstrating proof of methodological concept rather than covering significant substantive ground. With that said, we do offer a hint of our broader substantive goal of detecting the spread of legal concepts between various topical domains. Specifically, with respect to enriching positive political theory, we believe union, intersect and compliment of the semantic and citation networks are really important. More on this point is forthcoming in a subsequent post…

Reading List — Law as a Complex System [Repost from May 15th]

picture-23

Several months ago, I put together this syllabus for use in a future seminar course Law as a Complex System. This contains far more content than would be practical for the typical 2 credit seminar. However, I have decided to repost this because it could also serve as a reading list for anyone who is interested in learning more about the methodological tradition from which must of our scholarship is drawn. If you see any law related scholarship you believe should be included please feel free to email me.

Artificial Intelligence and Law — Barcelona 2009

AI & Law

Live from Barcelona, we are on the road at the International Association for Artificial Intelligence and Law.  Henry Prakken has just delivered the keynote address and we will soon be giving our presentation. The conference is interesting as it embraces a wide range of topics and intellectual traditions. For example, there is a significant emphasis on ontological reasoning, computational models of argumentation and the use of XML schemas. In addition, there are a number of folks using graph theoretic techniques and applying them to the development of the law. It has been a nice few days and we have enjoyed our time here. Tomorrow, the trip continues…. 

On the Road Again… Trip to Colorado Law School

Colorado Law

We just finished a few very interesting days at Colorado Law School. Given the intersect of Computer Program and Law is a fairly narrow set, it was great to spend sometime time at CU Law School because its faculty features two scholars with a significant programming background — Paul Ohm and Harry Surden. 

In addition to discussing CLS, we participated in a workshop on New Institutional Economics (NIE) and Law. I found this workshop very interesting as outside of my work in Computational Legal Studies, I have authored scholarship at the crossroads of New Institutionalism and Constitutional Political Economy.  For example, I have this article and this work in progress. My work follows the tradition of the Bloomington School of NIE. In two weeks, I will be presenting work in progress at ISNIE in Berkeley. 

Following the Colorado NIE Workship, we participated in the Silicon Flatirons Government 3.0 roundtable. I do not want to preempt the forthcoming white paper but I will say that it was a very worthwhile discussion.  It solidified my views on some topics and changed my mind on some others. So, the road show continues… AI & Law in Barcelona starts tomorrow… so light blogging for the next week. But as I like to say… more to come… 

Visualization of the Ideological History of the Supreme Court

USSC MQ Scores

Here is a cool visual for the Martin-Quinn Scores. For those of you not familiar, the Martin-Quinn paper and “MQ Scores” represented a significant breakthrough in the field of judicial politics. On that note, Stephen Jessee & Alexander Tahk have done a nice job both bringing their data up to date and extending their work.  For those interested, click on the visual above and check out all of the relevant links contained within this post.  

Tracking the TARP [From Information Aesthetics]

TARP

Information Aesthetics is now highlighting Subsidyscope — a project designed to track how various institutions receive federal monies.  Of particular interest is their visualization of disbursements under the Troubled Asset Relief Program (TARP). Sponsored by the PEW Charitable Trust, the site also contains .csv files for most of the underlying data.

An Exchange in Need of Empirics and an Analytical or Computational Model


section 5

On a recent flight, I read Jeffrey Toobin’s New Yorker Article on Chief Justice Roberts entitled “No More Mr. Nice Guy”.  The exchange quoted above is drawn from this article. While I believe it is appropriate to engage empirical data where available, the underlying discussion is not one exclusively subjectable to empirical inquiry.  Rather, it is, at least in part, a question in need of a formal theoretic model. Justice Roberts and Mr. Katyal are implicitly discussing a “state of the world” not yet realized but which would be realized if the statute were not to exist. What would benefit the discussion is principled manner to adjudicate between these two inferences drawn above.  Namely, it would be useful to fully evaluate what behavior would likely follow if the statute were not to exist.

There exist a variety of mathematical modeling techniques which could inject some much needed rigor into the above discussion. To my knowledge, such an applied model has yet to be offered.  The Supreme Court’s decision in the matter is soon forthcoming. Given the nature of the exchange above, there is reason to believe that if Chief Justice Roberts prevails ….we will get our model as the “state of the world” discussed above will no longer be hypothetical….