1. The Semantic Web: A network of understanding
Jim Hendler
Univ of MD/RPI

2. Outline The Semantic Web Past Present Future May, 2001 March, 2000

3. Semantic Web hypothesis: Heterogeneous Web-based Information Resources can be connected by Web-based knowledge models
PVT
Burkitt’s Lymphoma
Rearrangement of a DNA
sequence homologous
to a <cell-type>cell-virus junction
fragment </cell-type>in several <disease>Moloney murine leukemia</disease>
virus-induced <organism>rat</organism> thymomas
PubMed
Semantic Web
Oncogene(MYC):
Found_In_Organism(Human).
Gene_Has_Function(Transcriptional_Regulation).
Gene_Has_Function(Gene_Transcription).
In_Chromosomal_Location(8q24).
Gene_Associated_With_Disease(Burkitts_Lymphoma).
PVT
Burkitt’s Lymphoma
Rearrangement of a DNA
sequence homologous
to a cell-virus junction
fragment in several Moloney
murine leukemia
virus-induced rat thymomas
8q24
PVT1
PubMed

4. Web ontologies Web Ontologies are models allowing the linking of
multimedia
databases
services
Web services
Grid computing
meta-data repos
Or any other Web resource!
Other ontologies
Anything with a URI

5. The "layercake"
T. Berners-Lee, 2001

6. 2001 Research, experimentation, early demonstrations
Recommendation
WG activity
Funded Research
Research, experimentation, early demonstrations
Reminiscent of the early days of the Web
Jim

7. 2003 Early government adoption Emerging corporate interest
Recommendation
WG activity
Funded Research
Early government adoption
Emerging corporate interest
Jim

8. 2005 Commercial tools Lots of open source software Scalability
Recommendation
WG activity
Funded Research
Jim
Commercial tools
Lots of open source software
Scalability

9. Web Modeling Languages - 2005

10. 2006: You Are Here!
Ora

11. Significant Corporate Activity
Semantic (Web) technology companies starting & growing
Siderean, SandPiper, SiberLogic, Ontology Works, Intellidimension, Intellisophic, TopQuadrant, Data Grid, …
Bigger players buying in
Adobe, Cisco, HP, IBM, Nokia, Oracle, Sun, Vodaphone… announcements/use in
Gartner identifies Corporate Semantic Web as one of three "High impact" Web technologies
tools being announced: AllegroGraph, Altova, TopBraid, …
Government projects in and across agencies
US, UK, EU, Japan, Korea, …
Life sciences/pharma an increasingly important market
Health Care and Life Sciences Interest Group at W3C
Many open source tools available
Kowari, RDFLib, Jena, Sesame, Protégé, SWOOP, Onto(xxx), Wilbur, …
Ora

12. Data harvesting & visualization Enterprise data integration
Richer metadata
Embedded meta-data
Ora
Data harvesting & visualization
Enterprise data integration
"Corporate Semantic Web", Gartner "hot pick" for 2006

13. Digital asset management Semantic Web portals
Jim
Ontology editors (and other tools)
Semantic Web and social networking

14. Significant Corporate Activity
50+ Semantic Web press releases each month
Ora

15. Significant Government Activity
Agencies moving beyond the "talk" phase
primarily prototyping, but first acquisitions starting
Example:
NASA is developing an enterprise data strategy around using existing data via Semantic Web integration
Jim
(A. Schain, 3/06)

16. There's a Lot Out There! Paid ads 2,120,000 hits on "RDF filetype:rdf"
Jim
13,600 hits on
"ontology filetype:owl"
(March, 2006)

17. Where we are today Survey of 1300 OWL ontologies found by crawl
Wang 06
19 ontologies with classes
6 ontologies with classes
2 ontologies with classes
CYC, NCI
Species
RDFS
OWL Lite
OWL DL
OWL Full
Error
Count
587
199
149
337 3

18. Swoogle

19. Some "Swoogle" observations
The OWL namespace has been declared by 113,000 SWDs (8%) and actually used by 108,000 (7%). The RDFS namespace enjoys more use, being declared by 677,000 (47%) and used by 538,000 (37%) SWDs.
Owl:Class is the most used term from the OWL namespace with ~ 1, instantiations in 68,000 SWDs
We also noticed significant use of two OWL equality assertions: owl:sameAs (280,000 assertions in 17,00 SWDs) and owl:equivalentClass (70,000 assertions in 4,300 SWDs). Their common use may be an indication of increased ontology alignment.
(Ebiquity blog, Sept 1, 2006)

20. The cake is evolving as well..
(Tim Berners-Lee)
(Tim Berners-Lee)
2001
2006

21. New languages underway
SPARQL
Query language for (distributed) RDF triple stores
The SQL of the Semantic Web
GRDDL/RDFa
Integration of HTML world and Semantic Web
Means for "embedding" RDF-based annotation on traditional Web pages
Means for generating RDF triple stores from (annotated) Web pages
RIF
Rules interchange format
Representing rules on the Web
Linking rule-based systems together
And more
Multimedia annotation, Web-page Metadata annotation, Health Care and Life Science (LSID), Privacy

22. Next Steps

23. The Great Wall

24. Built in pieces at different times
Linked together for greater effect

25. The World Wide Web Built in pieces at different times
Linking of
"Web Islands"
Linked together for greater effect

26. Linking is power! Link to 45000 terms at NCI
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE rdf:RDF [
<!ENTITY feleuk.owl "
<!ENTITY owl "
<!ENTITY rdf "
<!ENTITY rdfs "
<!ENTITY NCI "
<!ENTITY CYC="
]>
<rdf:RDF xml:base="&feleuk.owl;"
xmlns:owl="&owl;"
xmlns:rdf="&rdf;"
xmlns:rdfs="&rdfs;"
xmlns:NCI="&NCI;"
xmlns:CYC="&CYC;">
<owl:Ontology rdf:about=""
rdfs:label="Feline Leukemia"
owl:versionInfo="Feline Leuk 1.0"/>
<owl:Class rdf:about="#Feline-Leukemia">
<rdfs:subClassOf rdf:resource="NCI:Leukemia"/>
<rdfs:subClassOf>
<owl:Restriction>
<owl:allValuesFrom rdf:resource="CYC:cat"/>
<owl:onProperty rdf:resource="#NCI:diseased-organism"/>
</owl:Restriction>
</rdfs:subClassOf>
</owl:Class>
</rdf:RDF>
Linking is power!
Link to 45000
terms at NCI
Link to (Open)CYC terms

27. We must link these together for great effect!!
Linking is power
Today we can find thousands of ontologies
Available on the Web
Linked to Web resources
Linked to data resources
Linked to each other
Linked to Web 2.0-like annotations
And billions of annotated (semi-Knowledge engineered) objects
Linked to the ontologies
We must link these together for great effect!!

28. A key opportunity Vast amounts of "semi-engineered" knowledge
Flickr: tens of millions of keyword tagged photos
Wikipedia: thousands of carefully documented subjects (in a hierarchy, with disambiguation, …)
Etc. etc. etc.
With "persistent" URIs
"tank" (armament)
"tank" (small town in Pakistan)
And anything with a URI can be linked to the Semantic Web!!!!!

29. For exciting linking possibilities
Linking of Web 2.0 and Semantic Web
Using informal KE to bootstrap "formal" KE
Extending formal KE from Web 2.0

30. Evolving vision Documents, linked to Images, annotated with
Ontologies, linked to
Other ontologies, describing
Databases, exported as
RDF graphs, as input to
Services, which designate
Documents, linked to …
(ad infinitum)
Stay tuned…
2001
2000
1994

31. Semantic Web Challenges
Today's Semantic Web Languages
Are not-very-expressive-KR-language standards
Not KIF, or even KL-ONE
Create non-persistent knowledge bases
Servers come and go
Ontologies change over time
And can't be kept consistent
Disagreement, error, dishonesty…

32. Semantic Web opportunities
Today's Semantic Web Languages
Are not-very-expressive-KR-language standards
Like HTML is to SGML
Create non-persistent KBs
Like the 404 error (w/o which there is no Web)
And can't be kept consistent
Like blog-space and Web 2.0
We need to accept, and more importantly exploit, these features

33. Note to Grad students (and their advisors)
The Semantic Web today, esp at the ontology layer, is like the Web with no one using <a href=…>
What makes the Web, the Web
Please, No more one ontology, one domain, one set of services, one … Theses
There's a reason we built this stuff on top of RDF and URIs
The network effect is where the power is!

34. A few of the many things I've left out
Semantic Web Services
Crucial for linking "programs" into the mix
Semantic Web tools and scaling issues
Engineering approaches being used to scale Semantic Web stores to database sizes
Information extraction and Semantics
Can we "retrofit" semantics on the existing Web
Semantic Web Information Creations
Can we make it so we don't have to retrofit future Web?
Other information resources
Personal data, unstructured resources, off-line collection information, digital libraries, …
There's more that isn't on the Web than is on it!
New Web use patterns
Social networks, blogs, wikis, …
… are all fertile areas for Semantic Web exploration

35. Conclusion The Semantic Web is real Development continues
Tremendous progress in the past five years
Lots of it is out there
Growing support in industry and govt use
Development continues
Easy to get involved
Many open source tools
New languages and techniques reaching critical mass
The next steps are exciting
The "network effect" of linking to other Semantic Web resources
… and to non-Semantic Web resources
And research opportunities still abound
Scaling
Inconsistency
Access and acquisition

36. The SEMANTIC WEB