Introducing the Semantic Web

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Introducing the Semantic Web

• Professor James Hendlerhttp//www.cs.umd.edu/hen
  dler
• Co-Director, Maryland Information and Network
  Dynamics Laboratory
• Semantic Web Agents Project
• http//www.mindswap.org

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(No Transcript)
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The Evolving Web
DATA/PROGRAMS
DOCUMENTS
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Web Semantics
Semantic Web LayerCake (Berners-Lee,
99Swartz-Hendler, 2001)
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Cant we just use XML?
This is what a web-page in natural language
looks like for a machine
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XML helps
XML allows meaningful tags to be added toparts
of the text
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XML ? machine accessible meaning
But to your machine, the tags look like this.
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Schemas take a step in the right direction
Schemas help.
lt CV gt
by relating common termsbetween documents
private
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But other people use other schemas
Someone else has one like this.
?namegt
lteducgt
lt CV gt
ltgt
lt????gt
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The semantics isnt there
lt CV gt
which dont fit in
private
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KR provides external referents to merge on
nme
CV
CV
work
vate
CV
educ
educ
SW languages add mappings And structure.
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Which is 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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Putting semantics on the web
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(and making it machine-readable)
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Eventtitle
ltdamlObjectProperty rdfID"photograph"gt ltrdfsdo
main rdfresource"Picture"/gt ltrdfsrange
rdfresource person"/gt lt/damlObjectPropertygt
EventWebPage
lt gt rdftype photoPhotograph, PhotoFile
http///imagesimage1, Phototopic
event1eventspeaker.
Event1 a Eventevent date May 7-11,
speaker http//timbl.html Title WWW
2002 TimBL rdftype w3c-ontperson name
Tim Berners-Lee
ltsClass rdfabout"http//www.semanticweb.org/ont
ologies/swrc-onto-2000-09-10.damlConference"gt lts
commentgt describes a generic conceptabout events
lt/scommentgt ltssubClassOf
rdfresource"http//www.semanticweb.org/ontologie
s/swrc-onto-2000-09-10.damlEvent"/gt ltadisjointFr
om rdfresource"http//www.semanticweb.org/ontolo
gies/swrc-onto-2000-09-10.damlWorkshop"/gt ltarest
rictedBy rdfresource"http//www.semanticweb.org/
ontologies/swrc-onto-2000-09-10.damlgenid18"/gt
ltrdfDescription rdfabout"http//www.w3.org/200
1/03/earl/0.95Person"gt ltrdftype
rdfresource"http//www.w3.org/2000/01/rdf-schema
Class"/gt ltrdfssubClassOf rdfresource"http//ww
w.w3.org/2001/03/earl/0.95Assertor"/gt lt/rdfDescr
iptiongt
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On the Web -- links are critical!
Web page
Any Web Resource
lta href
URIgt
HTML
lta hrefhttp//gt
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RDF graphs resemble semantic nets
DOC1
ltmindPerson rdfidHendlergt ltmindtitle
jobsProfessorgt ltjobsplaceOfWork
http//www.cs.umd.edugt lt/mindPersongt
Jobs
Mind
Professor
DOC1
Mindtitle
Hendler
Jobs
Web Page http//www
JobsplaceOfWork
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Semantics on the WEB

• RDF, like the WWW itself, is not separable
• Thinking about the ontologies, without
  considering
• The links to other terms
• The instances that link to them
• The crawling and collecting of ontological
  terminologues
• Is like thinking about the Web without the
  links!!

OtherProfessors
Othertitles
OtherPages
Jobs
Mind
Professor
OtherURIs
DOC1
Mindtitle
Hendler
Jobs
Web Page http//www
JobsplaceOfWork
Otherdescriptions
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Radically new view of Semantics
some partial mapping
Distributed,partially mapped, inconsistent -- but
SCALEABLE!
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Real examples

• Examples from http//dormouse.cs.umd.edu8080/wiki
  /cmsc498wiki.wiki
• Students violated every rule in the KR book
• Extended existing ontologies
• Linked instances directly to terms from multiple
  ontologies
• Mixed real KR and NL
• We can learn from their lessons
• http//dormouse.cs.umd.edu8080/wiki/assignment1_c
  ollected_les.wiki

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Current Activities
Semantic Web LayerCake (Berners-Lee,
99Swartz-Hendler, 2001)
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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
• DAMLOIL is submitted as a joint committee effort
  published as a W3C note .
• W3C WG Announcement in November 2001 -
  http//lists.w3.org/Archives/Public/www-rdf-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.
• Four Working Drafts to date
• Requirements/Use cases - March 2002
• 3 Technical Documents - July 2002 (Language
  renamed OWL)

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Membership

• Current Working Group includes over 50 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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But will it fly?

• DAMLOIL is already the most used ontology
  language ever!!
• http//www.daml.org (3.5M statements on 25,000
  web pages)
• Gaining acceptance by web players
• Semantic Web Track being offered at WWW 2002
• 3x more people attended WWW2002 Developer Day on
  SW than attended KR
• 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 DAMLOIL
• Much New Startup activity (even in this economic
  climate)
• Many tools being developed
• Many of them aimed at developers, not just AI
  literate types

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Making Markup Easier
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Machine worries about the syntax
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Use that markup in query/portal interfaces
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Extending ontologies on the fly
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Semantic Web Portals The Mosaic of the
semantic web?
ltXSLT/gt
ltOncogene rdfID"Oncogene, MYB"gtltcodegtC3682lt/code
gtltidgt3683lt/idgt ltFound_In_Organism
rdfID"Human"gtlt/Found_In_Organismgt ltGene_Has_Func
tion rdfID"Gene Transcription"gtlt/Gene_Has_Functi
ongt ltGene_Has_Function rdfID"Transcriptional
Regulation"gtlt/Gene_Has_Functiongt ltIn_Chromosomal_L
ocation rdfID"6q22-q23"/gt lt/Oncogenegt
ltOncogene rdfID"Oncogene NMYC"gt ltcodegtC17656lt/co
degtltidgt17657lt/idgtltFound_In_Organism
rdfID"Human"gtlt/Found_In_Organismgt ltIn_Chromosoma
l_Location rdfID"2p24.1"/gt ltGene_Has_Function
rdfID"Transcriptional Regulation"gt lt/Gene_Has_Fu
nctiongtltGene_Associated_With_Disease
rdfID"Neuroblastoma"gt lt/Gene_Associated_With_Dis
easegtlt/Oncogenegt
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Moving to the futureof the web
Semantic Web LayerCake (Berners-Lee,
99Swartz-Hendler, 2001)
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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 Cattlemans
  Cooperative, click here to run program.
• ...
• The sex network can answer anything that
  troubles you, click here for relief...
• The UFO network claims the all cows in Texas
  have been replaced by aliens

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Allows new capabilities
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Services off the desktop
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Or perhaps on different desktops
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Web Agents need Service Descriptions
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Semantic Web Service Description
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Use Semantics for Composition
Translate my symptoms fromFrench and find me a
pharmacythat has the necessary medicine(then
compute how to get thereand print the
directions)
Print the directions to a pharmacywhich has a
medicine that curesthe symptoms that I will tell
you (in French)
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Or, translate to Planning Operators
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For goal-based service composition
Buy the French version of a book from amazon.fr
and have it sent to Moms address
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Services need Web Logics
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Web of Trust

• Claims can be verified if there is supporting
  evidence from another (trusted) source
• We only believe that someone is a professor at a
  university if the university also claims that
  person is a professor, and the university is on a
  list I trust.

believe(c1) - claims(x, c1) predicate(c1,
professorAt) arg1(c1, x) arg2(c1,
y) claims(c2, y) predicate(c2,
professorAt) arg1(c2, x) arg2(c2,
y) AccreditedUniversity(y) AcknowledgedUniversit
y(u) - link-from(http//www.cs.umd.edu/universit
y-list,u)
Notice this one
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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!
• Were 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 exciting as heck
• Come play!

http//www.daml.org http//www.semanticweb.org htt
p//www.w3.org/2001/sw