i. The Web Ontology Language, OWL
ii. Future Direction
Prof. James Hendler
University of Maryland
Hendler@cs.umd.edu
http://www.cs.umd.edu/~hendler
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You are here
You
Are
Here
Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
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What the Web was meant to be
"This is a pity, as in fact documents on the web describe real objects and imaginary
concepts, and give particular relationships between them... For example, a document
might describe a person. The title document to a house describes a house and also the
ownership relation with a person. ... This means that machines, as well as people
operating on the web of information, can do real things. For example, a program could
search for a house and negotiate transfer of ownership of the house to a new owner.
The land registry guarantees that the title actually represents reality.”
 Tim Berners-Lee plenary presentation at WWW Geneva, 1994
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
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Event:title
<daml:ObjectProperty rdf:ID="photograph">
<rdfs:domain rdf:resource="#Picture"/>
<rdfs:range rdf:resource= …#person"/>
</daml:ObjectProperty>
Event:WebPage
< > rdf:type photo:Photograph,
Photo:File http://…/images#image1,
Photo:topic :event1#event:speaker.
Event1 a Event:event;
date “May 7-11”,
speaker http://…#timbl.html
Title “WWW 2002…”
TimBL rdf:type w3c-ont:person;
name “Tim Berners-Lee”
…
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<s:Class
rdf:about="http://www.semanticweb.org/o
ntologies/swrc-onto-2000-0910.daml#Conference">
<s:comment>
describes a generic conceptabout events
</s:comment>
<s:subClassOf
rdf:resource="http://www.semanticweb.or
g/ontologies/swrc-onto-2000-0910.daml#Event"/>
<a:disjointFrom
rdf:resource="http://www.semanticweb.or
g/ontologies/swrc-onto-2000-0910.daml#Workshop"/>
<a:restrictedBy
rdf:resource="http://www.semanticweb.or
g/ontologies/swrc-onto-2000-0910.daml#genid18"/>
<rdf:Description rdf:about="http://www.w3.org/2001/03/earl/0.95#Person">
<rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2001/03/earl/0.95#Assertor"/>
</rdf:Description>
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Semantic Web provides “external” models to merge on
nme
CV
CV
work
vate
educ
CV
ed
uc
<name
< name >>
<<educ
education> >
<> >
< work
SW languages add mappings
And structure.
<<
private>>
<< CV
CV >
A Usable “Modeling” language
 In science, models provide interoperability across jargons
 Mathematical models: equations of a system
 Physical models: “sticks and balls” of the atom
 Virtual models: the visualization of a complex data set
 INFORMATION MODELS: taxonomies and thesauris
 Ontologies extend thesaurus information models to provide
 Semantic restrictions on property relations
 Must have vs. May have vs. Doesn’t have
 Has some vs. has N vs. has 1
 Some vs. All property restrictions

Formal underpinnings
 Logical entailments
 Note: rules, logics, proofs are parts of ontologies, but not yet
at a “consensus” level for standardization

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Should build as add-ons to OWL to take advantage of “terminology
features”
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W3C Web Ontology Working Group
 Web Ontology Working Group in the W3C Semantic Web Activity aimed at
“extending the semantic reach of current XML and RDF meta-data efforts. “
 History





DAML+OIL is submitted as a joint committee effort published as a W3C note .
W3C WG Announcement in November 2001 - http://lists.w3.org/Archives/Public/wwwrdf-logic/2001Nov/0000.html
Weekly teleconferences started in November 2001
First Face to Face Meeting - New Jersey (Lucent), Jan ‘02; 2nd - Amsterdam April (W3C);
3rd - CA (Fujitsu/Stanford host) July; 4th in Bristol UK (HP Host) Oct.
First version Working Drafts now complete
 Requirements/Use cases
 3 Technical Documents - July 2002 (Language renamed OWL)
 3 “using it” Documents - November 2002
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Membership
 Current Working Group includes 55 members from over 30 organizations.

Chairs
 J. Hendler, MIND Lab UMCP
 G. Schreiber, Univ. of Amsterdam

Industry including:
 Large companies - Daimler Chrysler, IBM, HP, Intel, EDS, Fujitsu, Lucent, Motorola, Nokia,
Philips Electronics, Sun, Unisys
 Newer/smaller companies - IVIS Group, Network Inference, Stilo Technology, Unicorn
Solutions

Government and Not-For-Profits:
 US Defense Information Systems Agency, Interoperability Technology Association for
Information Processing, Japan (INTAP) , Electricite De France, Mitre, NIST

Universities and Research Centers:
 University of Bristol, University of Maryland, University of Southamptom, Stanford
University
 DFKI (German Research Center for Artificial Intelligence), Forschungszentrum Informatik,
Ontoweb

Invited Experts
 Well-known academics from non-W3C members (Hayes, Heflin, Stein, Borden)
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Use Cases for Ontologies
 Abstracted six categories of Use case from approx 25 real-world
applications/prototypes

Web Portals
 Categorization rules enhance search

Multimedia Collections
 Content-based searches for non-text media

Corporate Web Site Management
 Taxonomical Organization of documents
 Mapping Between Corporate Sectors (mergers!)

Design Documentation
 Explication of "derived" assemblies (e.g. wing spar)
 Explicit Management of Constraints

Intelligent Agents
 User Preferences/User Interests
 Content Mapping

Ubiquitous Computing
 Web Service Discovery and Composition
 Rights Management and Access Control
 Context-dependent content reformating
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OWL extends RDF…
Other
Professors
Other
titles
Mind:
Other
URIs
Jobs:
Jobs: Professor
Mind:title
DOC1
Hendler
Jobs:placeOfWork
Other
descriptions
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Web Page
http://www…
Other
Pages
rdfs:Class rdf:ID="Meeting">
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#MeetingName"/>
<daml:toClass
rdf:resource="http://www.w3.org/2000/10/XMLSchema#string"
/>
<daml:cardinality>1</daml:cardinality>
</daml:Restriction>
</rdfs:subClassOf>
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#uri"/>
<daml:toClass
rdf:resource="http://www.w3.org/2000/10/XMLSchema#uriRefer
ence"/>
<daml:maxCardinality>1</daml:maxCardinality>
</daml:Restriction>
</rdfs:subClassOf>
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#location"/>
<daml:toClass
rdf:resource="http://www.w3.org/2000/10/XMLSchema#string"/>
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OWL extends RDF…
 RDF-schema


Class, subclass
Property, subproperty
 + Restrictions




Range, domain
Local, global
Existential
Cardinality
 + Combinators



Union, Intersection
Complement
Symmetric, transitive
 + Mapping


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Equivalence
Inverse
rdfs:Class rdf:ID="Meeting">
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#MeetingName"/>
<daml:toClass rdf:resource="http://www.w3.org/2000/10/XMLSchema#string"/>
<daml:cardinality>1</daml:cardinality>
</daml:Restriction>
</rdfs:subClassOf>
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#uri"/>
<daml:toClass rdf:resource="http://www.w3.org/2000/10/XMLSchema#uriReference"/>
<daml:maxCardinality>1</daml:maxCardinality>
</daml:Restriction>
</rdfs:subClassOf>
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#location"/>
<daml:toClass rdf:resource="http://www.w3.org/2000/10/XMLSchema#string"/>
<daml:cardinality>1</daml:cardinality>
</daml:Restriction>
<rdfs:subClassOf>
<daml:Restriction>
<daml:onProperty rdf:resource="#Issues" />
<daml:toClass rdf:resource="#Issue" />
<daml:minCardinality>0</daml:minCardinality>
</daml:Restriction>
</rdfs:subClassOf>
</rdfs:Class>
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WOWG Documents
 Following Documents available
 Requirements for a Web Ontology Language (WD)
 Owl 1.0 Feature Description (WD)
 Owl 1.0 Reference Document (WD)
 Owl 1.0 Abstract Syntax Document (WD) (Not LC document)
 Owl 1.0 Semantics (Model Theory) (WD)
 Owl 1.0 Guide and Walkthru (WD)
 Owl 1.0 Test Suite (WD)
 Coming soon
 Non-normative appendices
 XML schema for OWL documents
 UML presentation syntax for OWL
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OWL is starting to move
 Based on DAML+OIL - the most used ontology language
ever!!

http://www.daml.org (6M statements on over 20,000 web pages)
 Gaining acceptance by web players
 Semantic Web Track was offered at WWW 2002 again at WWW 2003
 Strong attendance at WWW2002 Developer Day on SW
 Significant (international) Govt Support
 US DARPA/NSF; EU IST Framework 5,6
 Japan, Germany, Australia considering significant investments
 US National Cancer Institute to publish cancer vocabulary in DAML+OIL
 Much New Startup activity (even in this economic climate)
 Many tools being developed
 Starting to see tools for users, not just developers (but a long way to go)
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The Semantic Web “Revolution”
Scientific American Article notes
[Joint start ing place:]
I.
Semantic Web Vision (TBL)
II. Wha t are the enab lers? (in s equence )
Screen Scraping (Ora and TB L)
Data on Web (Ora and TBL)
Zip code li nk be tween Data Bases (TBL)
Ontology Independ ence (JAH)
Effect of Scale (TBL)
“Then, a miracle occurs”
III. What can you do wit h it? (not nec essaril y in s equence )
Self -describing documents (JAH)
Logi c to encode… (TBL)
Services and Adve rtisi ng (Ora)
Devices (Ora)
Digit al Signa tures, Auth entication, and Trust (TBL)
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Making Markup Easier
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Common Metaphor across tools
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Use that markup in query/portal interfaces
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Moving to the futureof the web
Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
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“Know” how to process what’s on the web
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Off the desktop
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Or perhaps on different desktops…
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Web “travel agents”
How many cows are there in Texas?
Query processed: 73 answers found

Google document search finds 235,312 possible page hits.

Http://www…/CowTexas.html claims the answer is 289,921,836

A database entitled “Texas Cattle Association” can be queried for the
answer, but you will need “authorization as a state employee.”

A computer program that can compute that number is offered by the State of
Texas Cattleman’s Cooperative, click here to run program.
...
The “sex network” can answer anything that troubles you, click here for
relief...



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The “UFO network” claims the “all cows in Texas have been replaced by
aliens
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Use Semantics for Composition
Translate my symptoms from
French and find me a pharmacy
that has the necessary medicine
(then compute how to get there
and print the directions)
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Print the directions to a pharmacy
which has a medicine that cures
the symptoms that I will tell you
(in French)
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For goal-based service composition
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Buy the French version of a book from amazon.fr and
have it sent to Mom’s address
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Services need Web Logics
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Distributed trust relationships
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Distributed Trust
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Conclusion
 It is no longer a question of whether the semantic web will
come into being, it is already here!
 We’re already well past the starting gate



Web ontologies, term languages, “shims” to DB and services, research in
proofs/rules/trust
Standardization providing a common denominator for KR researchers as
well as web developers
Small companies starting to form, Big companies starting to move
 The current environment is open, encouraging, moving fast,
and really exciting


Read our documents
Use our tools
 We want to hear from you!
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