What other people think

Cherry-picking Jurix 2009 papers

Posted in OWL, Ontology, What other people think, artificial intelligence on January 4th, 2010 by Rinke HoekstraBe the first to comment

Just a first batch of cherries from the Jurix 2009 paper cake (online versions here):

Emerald: Legal Knowledge Engineering using OWL and Rules
András Förhécz, Gábor Kőrösi, András Millinghoffer and György Strausz

Emerald is a knowledge engineering environment developed by the people at the Budapest University of Technology and Economics together with Multilogic. The system is an extensive redesign of the Allex Gold system, which performed backward-chaining on Prolog like rules. Emerald is based on the OWL 2 language, and adds expressiveness in the form of aggregate functions (translatable to DL queries), and reasoning with incomplete knowledge (i.e. a local closed-world interpretation of property values). The system also uses a simple rule language to specify the flow of user interaction: rules indicate what property values must be filled before a class restriction is satisfied.

I think it’s unfortunate that this work was only accepted as a short paper, since this work may turn out to become very influential in enterprise-class legal assessment systems (e.g. it is a big step from the propositional calculus of ORACLE’s Haley Office Rules to OWL 2 DL). On the other hand, this work should really be presented at a venue such as OWLED or the KR workshop series as the system is essentially domain independent. From a more legal perspective, the system is described at a too technical level, leaving many issues unmentioned that are particular to (normative) legal knowledge, such as exceptions. Also, I feel the Hungarian language should drop some of its accents.

MetaLex Naming Conventions and the Semantic Web
Alexander Boer

As an XML standard for legal sources (laws, court proceedings etc.) MetaLex has been around for some time now (developed by the University of Amsterdam in 2001), but the relatively new CEN MetaLex brings a significant overhaul of the original design. The new mechanism for specifying naming conventions is but one aspect of this.  MetaLex names are used in self-identification of documents, citation of other documents, and inclusion of document components according to the FRBR levels of item, manifestation, expression and work. A naming mechanism is important for interchange between systems because local implementations may depend on different ways to combine property-value pairs in constructing the IRI’s used to uniquely identify bibliographic entities. In other words, insight in the way in which IRI’s are constructed helps in the discovery of owl:sameAs relations between entities. Arguably, this is a topic very much of interest to the linked open data community (e.g. considering the submissions to the Web of Data track at ESWC 2010, and European projects such as OKKAM).

This paper introduces the naming mechanism (which is quite intricate), and describes how the uniqueness of IRIs can be guaranteed by using a GRDDL transform for translating the property-value pairs encoded in the IRI to OWL class axioms (using nominals, and proper relations between the different FRBR levels). A DL classifier can then infer owl:sameAs relations between entities (individuals) described using the appropriate property value pairs.

Again, given the issues at hand in linked open data, this approach has potential well beyond the AI and Law community.

Rule-based versus Principle-based Regulatory Compliance
Brigitte Burgemeestre, Joris Hulstijn and Yao-Hua Tan

The paper discusses the problems surrounding regulatory compliance, and the influence of different legal systems in specifying regulations on the type of legal reasoning required for systems. The authors focus on rule-based versus principle-based regulations, and identify seven dimensions along which the two approaches differ:

  • temporal (ex ante vs. ex post),
  • conceptual (specific vs. general),
  • functional (little vs. large discretionary power),
  • representation (procedural vs. declarative),
  • background knowledge needed (little vs. a lot),
  • exception handling (strict vs. defeasible),
  • conflict resolution (no conflicts possible vs. tradeoff between weights)

They study these dimensions in the context of European (AEO) and US customs regulations (C-TPAT). It turns out that although AEO is mostly principle-based, and C-TPAT is mostly rule-based, both can indeed be positioned at a continuum on which strictly rule- or principle-based regimes form the extremes (as argued earlier by Cunningham and Sadiq et al.). The paper represents a case using Reason Based Logic (Verheij et al.) which illustrates the difficulty in deciding what to represent as a principle, and what to represent as a rule.

I think it is a good thing that the distinction between the two regimes is again brought to the attention of the AI and Law community (especially by authors not especially active in the field): it emphasises the bigger picture of one of the real challenges in AI and Law, namely the development of technology that can be broadly applied, rather than only to interesting, but highly specific problems.

… that’s it for now, more to come (I hope)

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Seven OWL 2 Drafts Published

Posted in OWL, Ontology, What other people think on October 10th, 2008 by Rinke HoekstraBe the first to comment

From the W3C Website:

The OWL Working Group published seven documents yesterday relating to the OWL 2 Web Ontology Language. OWL 2 extends OWL, a core standard of the Semantic Web, adding new features that users have requested and that software providers are prepared to implement. The documents are:

  1. Structural Specification and Functional-Style Syntax
  2. Direct Semantics
  3. RDF-Based Semantics (First Public Draft)
  4. Mapping to RDF Graphs
  5. XML Serialization
  6. Profiles
  7. Conformance and Test Cases (First Public Draft)

The first three documents form the technical core of OWL 2, which has both a traditional “direct” semantics (for OWL DL) and a new “RDF-based” semantics (for OWL Full). Documents 4 and 5 specify two different serializations for OWL ontologies, one based on RDF and one using XML more directly. Document 6 defines useful subsets of OWL which may be easier to implement or may better meet certain performance requirements. Finally, document 7 specifies conformance and will later enumerate the OWL 2 test cases. Five other documents are under development; but they are not yet ready for public review. Learn more about the Semantic Web Activity.

SPARQL DL

Posted in OWL, What other people think on November 3rd, 2007 by hoekstraBe the first to comment

Bijan Parsia introduced the ideas of a SPARQL-like language that uses DL constructs at the ESWC 2007 OWLED workshop. The guys at Clark&Parsia really got busy, and the first implementation of SPARQL-DL will be introduced as part of Pellet.

While reading the more recent post, about query optimization, I wondered whether it is foreseen that SPARQL-DL will support CONSTRUCT queries.

One of the bigger problems in OWL knowledge-base manipulation is that it is often necessary to assert new individuals or classes based on assertions already available in the KB, e.g. in computing the outcome of some process or change. This is where SPARQL-DL constructs would really come in handy, as we can then use variables to both match and construct OWL definitions. Regular SPARQL doesn’t really help, as it only allows you to query and construct an RDF graph.

ISWC 2006 & OWLED 2006

Posted in OWL, Ontology, What other people think on November 20th, 2006 by hoekstraBe the first to comment

I’ve put a report of my trip to the ISWC 2006 conference & OWLED 2006 workshop in the States online at:

http://wiki.leibnizcenter.org/index.php/ISWC_2006

The page contains information about (most of) the talks I attended, and links to papers, interesting applications etc. (it’s a bit too big for a blogpost)

Verkiezingen…

Posted in NL, What other people think on October 27th, 2006 by hoekstra1 Comment

Aangezien de verkiezingen er aan zitten te komen, raad ik mijn vader aan om eens het KiesKompas te proberen.

De volgende ochtend ontvang ik een email met de volgende inhoud:

“Tjeemig; Nu worden mijn conservatieve pijnpunten zichtbaar. Gelukkig blijf ik, alhoewel niet zo consistent, binnen de linkse/progressieve range.
Het zal toch de PvdA moeten worden, denk ik. Alhoewel….”De luis in de pels” speelt nog steeds een rol. Ik stem gewoon op de PSP en verder bekijken ze het maar. Wat? Kan dat niet? Wie bepaalt dat eigenlijk? Hunk?!”

Gaan ze zeker een beetje bepalen wat ik moet stemmen zeker… is dat nou Democratie?

Updated OWL 1.1 draft specification documents

Posted in OWL, Ontology, What other people think on October 25th, 2006 by hoekstraBe the first to comment

The maintainers of the OWL 1.1 website at http://owl1-1.cs.manchester.ac.uk/ have uploaded new versions of the OWL 1.1 draft specification. Listed are:

These documents are to be discussed at the OWLED 2006 workshop (nov 10-11).

Visor

Posted in Internet, What other people think on August 1st, 2006 by hoekstraBe the first to comment

Visor allows you to open a drop-down terminal window overlay thingy from any application (on a Mac, that is).

Why would I post this link here? Ah well, maybe because it’s cool… and perhaps because I am a little afraid I will forget to use it.

Ontology Definitions

Posted in Ontology, What other people think on August 1st, 2006 by hoekstraBe the first to comment

So what is an ontology actually…?

Well, you won’t (really) find the answer here.