Legal expert system

A legal expert system is a domain-specific expert system that uses artificial intelligence to emulate the decision-making abilities of a human expert in the field of law.^[1]:172 Legal expert systems employ a rule base or knowledge base and an inference engine to accumulate, reference and produce expert knowledge on specific subjects within the legal domain.

Purpose

It has been suggested that legal expert systems could help to manage the rapid expansion of legal information and decisions that began to intensify in the late 1960s.^[2] Many of the first legal expert systems were created in the 1970s^[1]:179 and 1980s.^[3]:928

Lawyers were originally identified as primary target users of legal expert systems.^[4]:3 Potential motivations for this work included:

• speedier delivery of legal advice;
• reduced time spent in repetitive, labour intensive legal tasks;
• development of knowledge management techniques that were not dependent on staff;
• reduced overhead and labour costs and higher profitability for law firms; and
• reduced fees for clients.^[5]:439

Some early development work was oriented toward the creation of automated judges.^[6]:386

Later work on legal expert systems has identified potential benefits to non-lawyers as a means to increase access to legal knowledge.^[4]:4

Legal expert systems can also support administrative processes, facilitating decision making processes, automating rule-based analyses^[7] and exchanging information directly with citizen-users.^[8]

Types

Architectural variations

Rule-based expert systems rely on a model of deductive reasoning that utilizes "if A, then B" rules. In a rule-based legal expert system, information is represented in the form of deductive rules within the knowledge base.^[9]

Case-based reasoning models, which store and manipulate examples or cases, hold the potential to emulate an analogical reasoning process thought to be well-suited for the legal domain.^[9] This model effectively draws on known experiences our outcomes for similar problems.^[10]:5

A neural net relies on a computer model that mimics that structure of a human brain, and operates in a very similar way to the case-based reasoning model.^[9] This expert system model is capable of recognizing and classifying patterns within the realm of legal knowledge and dealing with imprecise inputs.^[11]:18

Fuzzy logic models attempt to create 'fuzzy' concepts or objects that can then be converted into quantitative terms or rules that are indexed and retrieved by the system.^[11]:18–19 In the legal domain, fuzzy logic can be used for rule-based and case-based reasoning models.

Theoretical variations

While some legal expert system architects have adopted a very practical approach, employing scientific modes of reasoning within a given set of rules or cases, others have opted for a broader philosophical approach inspired by jurisprudential reasoning modes emanating from established legal theoreticians.^{[1] :183}

Functional variations

Some legal expert systems aim to arrive at a particular conclusion in law, while others are designed to predict a particular outcome. An example of a predictive system is one that predicts the outcome of judicial decisions, the value of a case, or the outcome of litigation.^[3]:932

Reception

While various forms of legal expert systems have been created and tested, none have become widely used or accepted within the mainstream practice of law.^[5]:2

Challenges

Domain-related problems

The inherent complexity of law as a discipline raises immediate challenges for legal expert system knowledge engineers. Legal matters often involve interrelated facts and issues, which further compound the complexity.^[5]:4[6]:386

Factual uncertainty may also arise when there are disputed versions of factual representations that must be input into an expert system to begin the reasoning process.^[5]:4

Computerized problem solving

The limitations of most computerized problem solving techniques inhibit the success of many expert systems in the legal domain. Expert systems typically rely on deductive reasoning models that have difficulty according degrees of weight to certain principles of law or importance to previously decided cases that may or may not influence a decision in an immediate case or context.^[9]

Representation of legal knowledge

Expert legal knowledge can be difficult to represent or formalize within the structure of an expert system. For knowledge engineers, challenges include:

• Open texture: Law is rarely applied in an exact way to specific facts, and exact outcomes are rarely a certainty. Statutes may be interpreted according to different linguistic interpretations, reliance on precedent cases or other contextual factors including a particular judge's conception of fairness.^[5]:4
• The balancing of reasons: Many arguments involve considerations or reasons that are not easily represented in a logical way. For instance, many constitutional legal issues are said to balance independently well-established considerations for state interests against individual rights.^[12] Such balancing may draw on extra-legal considerations that would be difficult to represent logically in an expert system.
• Indeterminacy of legal reasoning: In the adversarial arena of law, it is common to have two strong arguments on a single point. Determining the 'right' answer may depend on a majority vote among expert judges, as in the case of an appeal.^{[6]:386–387}

Time and cost effectiveness

Creating a functioning expert system requires significant investments in software architecture, subject matter expertise and knowledge engineering. Faced with these challenges, many system architects restrict the domain in terms of subject matter and jurisdiction. The consequence of this approach is the creation of narrowly focused and geographically restricted legal expert systems that are difficult to justify on a cost-benefit basis.^[5]:5

Lack of correctness in results or decisions

Legal expert systems may lead non-expert users to incorrect or inaccurate results and decisions. This problem could be compounded by the fact that users may rely heavily on the correctness or trustworthiness of results or decisions generated by these systems.^[13]

Examples

ASHSD-II is a hybrid legal expert system that blends rule-based and case-based reasoning models in the area of matrimonial property disputes under English law.^[10]:49

CHIRON is a hybrid legal expert system that blends rule-based and case-based reasoning models to support tax planning activities under United States tax law and codes.^[14]

JUDGE is a rule-based legal expert system that deals with sentencing in the criminal legal domain for offences relating to murder, assault and manslaughter.^[15]:51

The Latent Damage Project is a rule-based legal expert system that deals with limitation periods under the (UK) Latent Damage Act 1986 in relation to the domains of tort, contract and product liability law.^[16]

Split-Up is a rule-based legal expert system that assists in the division of marital assets according to the (Australia) Family Law Act (1975).^[17]

SHYSTER is a case-based legal expert system that can also function as a hybrid through its ability to link with rule-based models. It was designed to accommodate multiple legal domains, including aspects of Australian copyright law, contract law, personal property and administrative law.^[15]

TAXMAN is a rule-based system that could perform a basic form of legal reasoning by classifying cases under a particular category of statutory rules in the area of law concerning corporate reorganization.^[18]:837

Controversies

There may be a lack of consensus over what distinguishes a legal expert system from a knowledge-based system (also called an intelligent knowledge-based system). While legal expert systems are held to function at the level of a human legal expert, knowledge-based systems may depend on the ongoing assistance of a human expert. True legal expert systems typically focus on a narrow domain of expertise as opposed to a wider and less specific domain as in the case of most knowledge-based systems.^[5]:1

Legal expert systems represent potentially disruptive technologies for the traditional, bespoke delivery of legal services. Accordingly, established legal practitioners may consider them a threat to historical business practices.^[5]:2

Arguments have been made that a failure to take into consideration various theoretical approaches to legal decision making will produce expert systems that fail to reflect the true nature of decision making.^[1]:190 Meanwhile, some legal expert system architects contend that because many lawyers have proficient legal reasoning skills without a sound base in legal theory, the same should hold true for legal expert systems.^{[15]:pp.6–7}

Because legal expert systems apply precision and scientific rigor to the act of legal decision-making, they may be seen as a challenge to the more disorganized and less precise dynamics of traditional jurisprudential modes of legal reasoning.^[18]:839 Some commentators also contend that the true nature of legal practice does not necessarily depend on analyses of legal rules or principles; decisions are based instead on an expectation of what a human adjudicator would decide for a given case.^[3]:930

See also

• Applications of artificial intelligence
• Artificial intelligence and law
• Clinical decision support system
• Disruptive innovation
• HYPO CBR - a legal expert system
• Indeterminacy debate in legal theory
• Subject-matter expert

References

1. Susskind, Richard (1986). "Expert Systems in Law: A Jurisprudential Approach to Artificial Intelligence and Legal Reasoning". Modern Law Review. 49.
2. Schweighofer, Erich; Winiwarter, Werner (1993). "Legal Expert System KONTERM - Automatic Representation of Document Structure and Contents". DDEXA '93 Proceedings of the 4th International Conference on Database and Expert Systems Applications: 486. CiteSeerX 10.1.1.22.4751.
3. Berman, Donald H.; Hafner, Carole D. (1989). "The Potential of Artificial Intelligence to Help Solve the Crisis in Our Legal System". Communications of the ACM. 32 (8). doi:10.1145/65971.65972.
4. Thomasset, Claude; Paquin, Louis-Claude (1989). "Expert Systems in Law and the Representation of Legal Knowledge: Can we isolate it from the Why and the Who?" (PDF). Proceedings of the 3rd International Congress on: Logica, Informatica, Diritto: Legal Experts Systems. 1. Retrieved 26 October 2012.
5. Stevens, Charles; Barot, Vishal; Carter, Jenny (2010). "The Next Generation of Legal Expert Systems - New Dawn or False Dawn?" (PDF). SGAI Conference Proceedings. Retrieved 26 October 2012.
6. Schafer, Burkhard (2010). "ZombAIs: Legal Expert Systems as Representatives "Beyond the Grave"". SCRIPTed. 7 (2). Retrieved 26 October 2012.
7. Lodder, Arno; Zeleznikow, John (2005). "Developing an Online Dispute Resolution Environment: Dialogue Tools and Negotiation Support Systems in a Three-Step Model". Harvard Negotiation Law Review. 10: 293. Retrieved 26 October 2012.
8. Svensson, Jörgen S. (2005). Encyclopedia of Information Science and Technology. Irma International. p. 1. Retrieved 26 October 2012.
9. Aikenhead, M. (1995). "Legal Knowledge-Based Systems: some observations on the future". Web JCLI. 2. Retrieved 26 October 2012.
10. Pal, Kamalendu; Campbell, John A. (1997). "An Application of Rule-Based and Case-Based Reasoning within a Single Legal Knowledge-Based System". The DATA BASE for Advances in Information System. 28 (4).
11. Main, Julie; Pal, Sankar K.; Dillon, Tharam; Shiu, Simon (2001). "A Tutorial on Case-Based Reasoning". in Soft Computing in Case Based Reasoning (PDF) (4th ed.). London: (Ltd). Retrieved 26 October 2012.
12. Franklin, James (2012). "'How much of commonsense and legal reasoning is formalizable? A review of conceptual obstacles". Law, Probability and Risk. 0: 11–12.
13. Groothuis, Marga M.; Svensson, Jörgen S. (2000). "Expert system support and juridical quality". Legal Knowledge and Information Systems. Amsterdam: Jurix 2000: The Thirteenth Annual Conference. p. 9.
14. Sanders, Kathryn E. (1991). "Representing and reasoning about open-textured predicates". ICAIL '91: Proceedings of the 3rd international conference on artificial intelligence and law. ICAIL. pp. 140–141.
15. Popple, James (1996). A Pragmatic Legal Expert System (PDF). Applied Legal Philosophy Series. Dartmouth (Ashgate). ISBN 1-85521-739-2. Archived from the original on 28 December 2006. Retrieved 10 August 2014.
16. Susskind, Richard (1989). "The latent damage system: a jurisprudential analysis". ICAIL '89: Proceedings of the 2nd international conference on artificial intelligence and law. ICAIL. pp. 23–32.
17. Zeleznikow, John; Stranieri, Andrew; Gawler, Mark (1996). "Project Report: Split-Up - A Legal Expert System which Determines Property Division upon Divorce". Artificial Intelligence and Law. 3: 268.
18. McCarty, L. Thorne (1997). "Reflections on Taxman: An Experiment in Artificial Intelligence and Legal Reasoning". Harvard Law Review. 90 (5).