Presentation Transcript
Introducing the Semantic Web : Introducing the Semantic Web Professor James Hendler http://www.cs.umd.edu/~hendler
Co-Director, Maryland Information and Network Dynamics Laboratory
Semantic Web Agents Project
http://www.mindswap.org
The Evolving Web : The Evolving Web DOCUMENTS DATA/PROGRAMS
Web Semantics : Web Semantics Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
Can’t we just use XML? : Can’t we just use XML? This is what a web-page in natural language
looks like for a machine
XML helps : XML helps XML allows “meaningful tags” to be added to parts of the text
XML machine accessible meaning : XML machine accessible meaning But to your machine,
the tags look like this….
Schemas take a step in the right direction : Schemas take a step in the right direction Schemas help…. < CV > …by relating
common terms between documents private
But other people use other schemas : But other people use other schemas < CV > name> <> <> Someone else has one like this….
The “semantics” isn’t there : The “semantics” isn’t there < CV > …which don’t fit in private
KR provides “external” referents to merge on : KR provides “external” referents to merge on SW languages add mappings
And structure. nme work vate educ CV CV educ
Which is what the web was meant to be!! : 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
Putting semantics on the web : Putting semantics on the web
(and making it machine-readable) : (and making it machine-readable)
Slide16 : Event:title 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” …
describes a generic conceptabout events
On the Web -- links are critical! : On the Web -- links are critical! HTML Web page Any Web Resource
RDF graphs resemble semantic nets :
DOC1 Hendler DOC1 Mind:title Jobs:placeOfWork Web Page
http://www… Professor Jobs: Mind: Jobs: RDF graphs resemble semantic nets
Semantics on the WEB : 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!! Hendler DOC1 Mind:title Jobs:placeOfWork Web Page
http://www… Professor Jobs: Mind: Jobs: Other Professors Other Pages Other titles Other descriptions Other URIs
Radically new view of Semantics : Radically new view of Semantics Distributed,partially mapped, inconsistent -- but SCALEABLE! = some partial mapping
Real examples : Real examples Examples from http://dormouse.cs.umd.edu:8080/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.edu:8080/wiki/assignment1_collected_les.wiki
Current Activities : Current Activities Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
W3C Web Ontology Working Group : 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/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)
Membership : 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)
But will it fly? : But will it fly? DAML+OIL 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 DAML+OIL
Much New Startup activity (even in this economic climate)
Many tools being developed
Many of them aimed at developers, not just AI literate types
Making Markup Easier : Making Markup Easier
Machine worries about the syntax : Machine worries about the syntax
Use that markup in query/portal interfaces : Use that markup in query/portal interfaces
Extending ontologies on the fly : Extending ontologies on the fly
Semantic Web Portals: The Mosaic of the semantic web? : Semantic Web Portals: The Mosaic of the semantic web? C36823683
C1765617657
Moving to the futureof the web : Moving to the futureof the web Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
Web “travel agents” : Web “travel agents” 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...
The “UFO network” claims the “all cows in Texas have been replaced by aliens How many cows are there in Texas?
Allows new capabilities : Allows new capabilities
Services off the desktop : Services off the desktop
Or perhaps on different desktops… : Or perhaps on different desktops…
Web Agents need Service Descriptions : Web Agents need Service Descriptions
Semantic Web Service Description : Semantic Web Service Description
Use Semantics for Composition : 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)
Print the directions to a pharmacy which has a medicine that cures the symptoms that I will tell you (in French)
Or, translate to Planning Operators : Or, translate to Planning Operators
For goal-based service composition : For goal-based service composition Buy the French version of a book from amazon.fr and have it sent to Mom’s address
Services need Web Logics : Services need Web Logics
Web of Trust : 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)
AcknowledgedUniversity(u) :- link-from(“http://www.cs.umd.edu/university-list”,u) Notice this one
Distributed Trust : Distributed Trust
Conclusion : 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 exciting as heck
Come play!
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