Erich Schweighofer University of Vienna, Austria.
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Transcript of Erich Schweighofer University of Vienna, Austria.
Erich Schweighofer University of Vienna, Austria
Outline (1)State of the art: legal research and legal
retrieval systems (TXT, HTML) + hypertext, + some meta informationN-Lex: Standard for exchange of legal
information Good start, but improvements necessary
Legal Semantic Web, Legal Social WebXML, RDF, RDF schema, OWL Knowledge management in legal units
Known applications: knowledge representation, conceptual information retrieval, advanced lexical thesauri, exchange standards (MetaLex)
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Outline (2)Other uses; more support for European
legal work?Status quo of legal searching insufficientExchange of electronic legal meta data a big
problem Need for a legal „Dublin Meta Core“
Future: Dynamic Electronic CommentarySupport tools for European legal work
Next stepsConclusions
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Text archive & retrieval (1)
Standard service Easy access and efficient handling of the now
so many legal documents Retrieval: discrimination task more and more
difficult (e.g. finding the Boolean combination that sufficiently selects only those documents I am interested in [e.g. finding 1 to 10 documents in a collection of 1 to x million documents])
Text archive & retrieval (2)Legal retrieval ≠ “To Google”
Exact legal provision (or paragraph in a legal judgement); not just some information available in a redundant way
No Social Web (e.g. lawyers as a community are linking sufficiently to important legal documents)
Only in law firms with efficient knowledge management possible
Semantic Web?
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Semantic WebTim Berners-Lee:
[T]he Semantic Web is "not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation”.
Standards for semantic information on the web Tagged and linked using the technologies of Resource
Description Framework (RDF), XML and URIs Web Ontology Language (OWL) Next layer: may be a logical one, an inference
machineRemains largely unrealised
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Legal web, legal text corpora and beyondLegal web = huge text corpora
Legal information systemsWeb sites
Boolean logic + hypertextSome mark-up (text structure)
Good coverage, easy handling of documentsProblem: semantic meaning and searching is
insufficiently developed Same situation as semantic web To do: adaptation of standards for mark-up +
implementation
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XML (eXtensible Markup Language)XML (eXtensible Markup Language)
General specification for creating markup languages
Subset of the Standard Generalized Markup Language (SGML) but human-legible
Free standard of the W3C; versions 1.0 and 1.1 Recommendation XML 1.1 (Second Edition):
http://www.w3.org/TR/2006/REC-xml11-20060816/ Structure has to be represented like a tree Document type definition (DTD)
Mark-up tags are freely extensible Allows semantic mark-up Law: definition of semantic document structure,
e.g.: <!ELEMENT judgement (title, summary, grounds, operational part, citations*)>
Attribute values Automatic verification
XML (2)Valid documents conform with a particular
DTD/schemaXML schema definition (XSD)
Successor of DTDsXML Style Sheet
Extensible Style Sheet Language (XSL) Client-side XSLT XML-based document transformation language
Extensible Linking and Pointer Languages XLink: simple and multiple linksXpointer: links to other document parts
Browser: Internet Explorer from version 5.0File format: OpenOffice, Word2007DTD for legal documents for Electronic Data
Interchange (EDI)
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Why XML?Why XML?Advantages
Semantic meaning for syntactic data <name>schweighofer</name> Reuse + recycling of information Change of layout Improved searching of documents Unicode Open document format
Disadvantages Hierarchical model for representation has its limits Redundancy of data
Main uses in law Interchange of documents Interchange of knowledge
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RDF (Resource Description RDF (Resource Description Framework)Framework)RDF syntax
Description of meta data in web documentsEach data can be linked with a file that describes the type of
this data. Recommendation: http://www.w3.org/TR/2004/REC-rdf-
primer-20040210/ RDF statement: subject-predicate-object expression
(triples in RDF terminology) Subject (described websource = URL) – predicate (attribute,
e.g. author) – object (value, e.g. name)Query language for RDF graphs: SPARQL Semantic web
Automated storage, exchange and use of machine-readable information on the web
Applications: exchange and common use of web data, improved implementation of search engines, classification of a website (also with software agents) etc.
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RDF SchemaRDF SchemaExtensible knowledge representation languageLanguage for description of the structure, the content
and the semantic of XML documentsBasic elements for the description of ontologies (RDF
vocabularies) Recommendation: 10.2.2004:
http://www.w3.org/TR/2004/REC-rdf-schema-20040210/A RDF scheme does not only describe predicates of a web
source (e.g. title, author, etc.), but also the kind of the described sources (e.g. books).
Development of user-oriented RDF vocabulariesObject-oriented description of data structures with
multiple heritageClasses, predicates, constraints
Ontology for exchange of data on the WebImportant initiatives: Dublin Core Metadata Initiative,
PICS labels, P2P
Web Ontology Language (OWL)Family of knowledge representation languages
for developing ontologiesRevision of the DAML+OIL web ontology language W3C standard 10 February 2004
http://www.w3.org/2004/OWL/Two semantics based on Description Logics
OWL-DL All OWL language constructs
OWL-Lite Classification hierarchy and simple constraints (not widely used)
RDF/XML syntaxLKIF Core Ontology (Leibniz Center for Law,
Amsterdam)
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Semantic Web & ontologiesSemantic Web: highly developed description
languages existMerger between web & ontologies envisaged Quantity of mark-up so far insufficient
Legal semantic webSemantic mark-up of legal information systems should
be re-used Field structures Thesauri Citations
AI & law (legal logic, conceptual information retrieval etc.)
Incorporation of world ontologies
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Legal thesauriLegal thesauri
ISO 2788 standard Definition
Precompiled list of important words in a given domain of knowledge (controlled vocabulary)
Concepts are linked with relations Synonyms (polysems), antonyms, broader term, narrower
term, homonyms Dictionary: definitions
Information science + legal information systems Documentation and retrieval
Nucleus of a lexical ontology
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Legal ontologiesExplicit formulation of a legal domain
Thesauri + definitions + more relations + formalisation for IT applications
Conceptual model Abstract, simplified, computable
New form of abstraction and formalisation of law Theory of formalisation (?)
Advantages Computable Links with world ontologies Re-use of existing ontologies Important tool for automation of law
Problems High efforts required for knowledge acquisition Scaling-up (well-known problem in AI & law)
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Related workEarlier formalisation attempts
Hohfeld, Allen, McCarty, Stamper etc.1990ies
FOLaw (Valente), FBO (van Kralingen, Visser) Workshop on legal ontologies 1997
LOAIT Workshop on Legal Ontologies and Artificial Intelligence Techniques 2005 and 2007
ICAIL International Conference on Artificial Intelligence and Law Sessions on ontologies since 1997
LEX Legal XML Workshop Florence 2007Major research: Leibniz Center for Law, Amsterdam; ITTIG,
Florence; University of Turin, Autonomous University of Barcelona, University of Vienna etc.
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Types of applicationsRepresentation of legal knowledge
e.g. FBO, LRI Core, LKIF
Conceptual information retrievalJuriservice, LOIS
Advanced lexical ontologiesMultilingual thesauri
e.g. LOIS, Legal Taxonomy Syllabus
Interchange of documents and knowledgee.g. MetaLex, eLaw
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Knowledge representation (1)Language for Legal Discourse LLD / McCarty
(1989)NORMA / Stamper (1991)Frames-based ontology (FBO), van Kralingen and
Visser Common legal ontology; re-useable, 3 classes of model
primitives, for each class a frame structure has been defined with all relevant attributes
Functional ontology (FOLaw), ValenteAim: organisation and linking of legal knowledge, in
particular in respect to conceptual information retrieval6 basic categories of legal knowledge
Normative knowledge, meta-legal knowledge, world knowledge, responsibility knowledge, reactive knowledge, creative knowledge
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Knowledge representation (2)ON-LINE (architecture of legal case-solving)PROSA (training system for legal case-solving)
E-Court, LRI-Core, University of AmsterdamGoal: semi-automated multi-lingual information
management for various sources (audio, video, text); application area: penal law
LRI-Core: broad concept structure with typical legal main concepts About 200 concepts, in development anchors Links between foundational (upper) ontology (=
world knowledge) and legal core ontology (legal concepts)
Supports legal subsumption 22
Knowledge representation (3)Select/direct from various acts or agents to the legally
relevant onesE-Power, project of the Dutch Tax and Customs
Administration Application-oriented knowledge system; formalisation of laws
and regulations as conceptual models Automated tasks (e.g. subsumption, calculation, document
assembly); comprehensive support from legislation to application
LKIF Core Ontology (Legal Knowledge Interchange Format) (Estrella project), University of Amsterdam Standard OWL ontology OWL-DL (description logic) Description logic programs (DLP)
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Knowledge representation (4) Obligation, permission, roles, rights, duties, privileges,
liabilities etc. Top level clusters Mereological relations Location Time Changes (processes) Agents + actions + roles Propositions Legal agents + actions, rights, powers Norms LKIF rules – more expressive than OWL Application: traffic domain
Impressive standard
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Multilingual thesauri (1)LOIS Lexical Ontologies for legal Information
ServingMulti-lingual access to European legal databasesFormal representation of legal concepts in all languages
on the basis of the WorldNet technology; similar concepts6 languages, 5000 synsets ILI inter-lingual index + legal definitions10 partners; leader: ITTIG, Florence
Legal Taxonomy Syllabus (University of Turin)Tool to annotate and recover multi-lingua legal
information (EU Directives)Legal dictionaries Taxanomies of legal concepts
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Multilingual thesauri (2)DALOS (ITTIG, Florence)
Ontological-linguistic resource for multilingual drafting process (EU)
Basis: LOISOntological layer: conceptual modelling at a language-
independent level Lexical layer: lexical manifestations in different
languagesTerm extraction using NLP tools
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Advanced lexical ontologiesLOISLegal Taxonomy Syllabus JuriserviceDALOS Comprehensive legal ontology (University of Vienna)
Real world (world knowledge) Legal system as a order of norms : socio-economic
governance by law with the goal of risk reduction Frames
Material rules Procedural rules
Concepts Concept frames
Starting point legal thesauri, e.g. LOIS thesauri Links: world knowledge, rules, top legal ontology
Hard core of a legal ontology
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Interchange of documents and knowledgeInterchange standards for documents
Many international and European applicationse.g. EU, eLaw (Austria), MetaLex
Interchangability of legal knowledge representation MetaLex (University of Amsterdam)
Generic and extensible framework for XML-encoding of legal resources
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Dynamic Electronic Legal Commentary (1)
Abstract representation of law in a conceptual & logical-systematic structure; like printed commentary but in a machine-useable format
Description of the world ([possible] facts)The core: links between possible facts (situations)
and legal consequencesProblem: world ontologies have still some way to
improve sufficiently, legal formalisation has to move from small environments to the real big world
It‘s time to move on
Dynamic Electronic Legal Commentary (2)For legal information systems: Not the very, very big step, but :
Tools like a navigator [time and document types, layers of the legal order, consolidated texts] (e.g. PreLex) , citator or terminologist are possible and would be highly desirable …
Thus good paying services
In the near futureThe real thing … some automated support for legal
subsumption, e.g. helping in the real game of applying legal provisions (could that also called legal reasoning or a legal expert system … maybe?)
European standard of legal ontologiesMotivators
Comparative legal research, harmonisation of EU law (e.g. Services Directive), European E-Government
Ontologies are standards, thus an obvious thing to doMeta information in Dublin Core Metadata
languageCitations (standard, URI)Ontological structures
RulesHaley Ltd. (formerly: Softlaw)
ConceptsE.g. lexical ontologies projects
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Next steps (1) Interchange of documents and knowledge
Legal documents: ongoing and improving Legislative documents: many applications, standards like
MetaLex may improve formalisations due to inclusion of knowledge representation aspects
Improvement and enlargement of legal thesauri Up to 10.000 concepts
URI formalisation of citations on an EU level Multilingual information retrievalConceptual information retrieval using legal thesauri
Improved searching, classification and summarisation of documents
Word sense disambiguation for easier coupling with legal information systems
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Next steps (2)Text analysis and text categorisation Start: information system (text archive)
Classification Concept analysis (e.g. DALOS, KONTERM) (Semi)automatic text analysis
Summaries (e.g. SALOMON, KONTERM, FLEXICON)Result: semantic description of the legal order; some
“primitive” anchors to legal system and world knowledge
Inclusion of results of text analysis in an advanced lexical ontology
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Next steps (3)Concept frame
Header, definition, relations + More relations, better definitions, links to legal rules +
world knowledge “Raw” conceptual legal ontology
“Raw” dynamic electronic commentaryConceptual description of legal order with links to legal
rules and world knowledge Formalisation of dynamic electronic commentary
in LKIF or other ontology languages Big step, resources not availableMore research required
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Conclusions Ontologies are the key for a computer-useable
formalisation of the knowledge on the world and the legal system
XML: standard for mark-up of legal documents XML/ontologies: emerging standard for knowledge
representation New form of a legal commentary: dynamic, electronic,
computer-useable Big support for European legal work
Legal search, exchange of data, exchange of knowledge Next steps
Exchange standards Multilingual information retrieval Improvement of legal thesauri Some (semi)automatic text analysis and categorisation,
advanced lexical ontologies Later: formalisation in LKIF
Big potential for easier better European legal work
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Contacts
Erich Schweighofer
Universität WienArbeitsgruppe Rechtsinformatik
Wiener Zentrum für Rechtsinformatik
http://rechtsinformatik.www.univie.ac.at
IRIS2009 Internationales Rechtsinformatik Symposion, Salzburg http://www.univie.ac.at/RI/IRIS2009