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An Open Source GUI for the Carneades Argumentation Framework

This proposal lays out an open source GUI for the Carneades argumentation framework for funding by Googles Summer of Code 2008 program. The project website is at http://carneades.plainreasoning.com.

Given the academic research context of the project, there is no suitable mentor organization among the list of possible mentors. Hence, this document is submitted as an alternate proposal. The mentors suggested at the end of the document have been contacted and expressed strong support for the proposal.

In order to facilitate understanding of the Carneades program and the benefits of a GUI, a brief overview of the field of Artificial Intelligence and the Law and formal legal argumentation will be given.

1. Introduction

The field of Artificial Intelligence conducts research on how legal reasoning, argumentation and processes can be formalized in a way to assist decision-makers, lawyers or civil servants in fulfilling their duties and help ordinary citizens understand their rights and duties under the law. The main research efforts in the field have focused on computational models of legal argument. Although a considerable number of models and formalizations have been developed, none of them has made it to a widespread application among practitioners.

With the recent development of the Carneades argument model, however, the field has experienced a very significant advancement. A bridge between state of the art argumentation theory and A.I. and Law has been established and made fruitful to solve various representational problems and integrate the whole into a single model. The main advancements of Carneades lie in its procedural approach to argument construction and its sophisticated burden of proof model.

An open source software library has been developed (http://carneades.berlios.de). It provides basic functionality for argument construction, evaluation, visualization and interchange. It contains a reasoning module based on a set of search strategies to build legal arguments from the knowledgebase. The models can be represented in XML format. With Carneades being open source, argumentation researchers now have the possibility to use the framework to develop their own argumentation models, schemes and applications based on the library.

Carneades is currently implemented in Scheme. The argumentation graphs (see the proposal website) are produced using GraphViz, a freely available visualization tool. This results in a cumbersome setup and a big threshold for constructing new applications based on Carneades as it does not supply a specially suited interface that would allow users other than the actual developer to interact with the environment. We propose the development of a GUI as described below to address this problem and help Carneades unfold its potential.

2. Conception of a Modular User Interface

The development of a modular open source GUI would greatly facilitate the usage of and third-party development with the Carneades framework. The overall concept is to provide a universal argumentation development environment, which enables the user to enter arguments, make changes to argument graphs and helps to control the search for new arguments. It shall visually resemble the commercially available tools, but combine them with Carneades advanced argumentation model.

The interface will be based on RIA technology and publicly accessible on the web. The latter is crucial as it enables creators of new argumentation schemes to easily produce an interactive version and present it to the public. This potentially enhances the fields productivity and allows for a much more effective exchange of ideas.

2.1 The Main Environment

The main environment functions as a front-end to the reasoner and provides a workspace. It will allow for argument modules to be arranged and configured into a structure that interconnects different reasoners with data compilations. The user will have a specific goal in mind and can interact with the system to find pro and con arguments. By reconfiguring the reasoning and adding, removing or altering the used data and arguments, the environment allows for ablation-like experiments and observations of argument models and their behavior.

In the main window workspace, all other components can be moved around or arranged in tabs. The core is a tree structure containing all data and reasoning modules involved and providing access to them. When the user runs the argument system, the environment constructs a query and executes it using the Carneades libraries. The produced results are then displayed and can the user can continue working with them.

2.2 Data Editing

There are four basic types of legal information currently used by Carneades. Precedent cases and statutory rules are sources of law and definition ontologies as well as testimonial evidence constitute supplementary knowledge for the reasoning process. Data is read in XML format using predefined schemes.

Other researchers who want to use Carneades with their own argument model only need to make their data accessible by using the means provided by the Carneades API. The result is a universal testing environment for any argument model once it has been interfaced with the standardized interchange format that Carneades uses.

2.3 Prospective Additions for Application Development

While above explanations describe an experiment-and-test environment for researchers, such an interface would open new possibilities for application and expert system development. Once an argumentation model has been sufficiently refined, tested and equipped with enough knowledge to reason about, the last step to practical application is to allow the input of case facts in a convenient way.

Before constructing an argument, Carneades currently establishes case facts by either retrieving them from XML files or querying the user. In the proposed GUI, those two methods can be embedded into the interface. For a real-world application, however, it would be necessary to comfortably generate forms for users to fill out and, once the submit-button is clicked, have Carneades produce an argument for the facts provided and show it to the user. By designing the GUI in an object-oriented way, the components can be reused to support a fast and convenient development of such legal argument applications.

3. Planned Implementation

The GUI will be developed using the Java FX SDK, as it allows the greatest possible flexibility with regard to interfaces with other, possibly non-web, applications and supports an object-oriented, modular architecture. It will then be available as open source with the Carneades library.

5. Developer

Matthias Grabmair is currently a first year Ph.D. student in the Intelligent Systems Program at the University of Pittsburgh, where here also earned his master degree in law after finishing his undergraduate law degree in Germany. Before his studies, he worked as an Internet developer for a German computer game publisher. A detailed CV can be found on the proposal website, where the development progress will also be monitored. His main field of work is A.I. and Law and he is in constant contact with the suggested mentors.

6. Mentors

Suggested mentors are Dr. Thomas F. Gordon at Fraunhofer Fokus in Berlin, the developer of Carneades, and Prof. Kevin Ashley at the University of Pittsburgh, both leading authorities in A.I. and Law.
Email: thomas.gordon_at_fokus.fraunhofer.de / ashley_at_pitt.edu

Mentors
Thomas F. Gordon
Kevin D. Ashley

Relevant Links
The Carneades Framework

Relevant Literature
Gordon: Visualizing Carneades Argument Graphs
Gordon/Prakken/Walton: The Carneades Model of Argument and Burden of Proof