The Semantic Web

The Semantic Web
The Next Evolution of the WWW
Company
LOGO
Summer 2005

Overview
• What is the Semantic Web
• Background
• Components of the Semantic Web
• Why the Semantic Web is needed
• Uses of the Semantic Web
• Implementing the Semantic Web
• Examples
• Conclusion

What is the Semantic Web
The Semantic Web is "an extended web of
machine-readable information and automated
services that amplify the Web far beyond
current capabilities" (Daconta et al.)
• A framework that:
Adds meaning to data
Provides a mechanism for organizing,
interpreting, and making use of that meaning

What is the Semantic Web (cont)
• An enhancement to the current Web, not a
replacement
“The Semantic Web will bring structure to the
meaningful content of Web pages, creating an
environment where software agents roaming
from page to page can readily carry out
sophisticated tasks for users” (Berners-Lee et
al.)

Background
• 1968 – Internet used as a communications
network by DOD
• 1989 – Tim Berners-Lee (and others) at
CERN develop HTML from SGML
• Early 1990s – Web browsers created to
interpret HTML
• 1996 – XML developed
• 1990s+ – Tim Berners-Lee & W3C
continue to pursue development the
Semantic Web

Components of the Semantic Web
• Four major components:
XML
Resource Description Framework (RDF)
Ontologies
Agents

Supplemental Components of the
Semantic Web
• Supplemental components
Uniform Resource Identifiers (URIs)
Web services
Inference rules
Service discovery
Semantic aware applications
Security and trust
XML and RDF schemas

XML
• HTML (XHTML) is a series of predefined
tags that add presentation to data
This text is bold
• XML is a series of user-defined tags that
add information to data
John Smith

XML (cont)
• Issue:
"XML has become the universal syntax for
exchanging data between organizations"
(Daconta et al.)
Some mechanism must exist for coordinating the
meaning of the user-defined tags and for
understanding the context of that information
Company A: Smith
Company B: Jones
Company C: Williams

Resource Description Framework
(RDF)
• An XML-based language used to describe
resources
• Resources can include entities, concepts,
properties and relations
• Captures the meta data about the
“externals” of a document
• Can use a serialized model, RDF triplets,
special notation, or graphs to describe
data

Resource Description Framework
(RDF) (cont)
• Example serialized model
• RDF triplet (subject, predicate, object/literal):
Predicate
Object
sells
Software
Subject
Company
Predicate
Literal
Is named
Microsoft
The company sells software
The company is named Microsoft
John Smith is the president of Company X
Next

Ontologies
“the common words and concepts (the
meaning) used to describe and represent an
area of knowledge" (Daconta et al.)
• Provide the repositories for meaning
interpretations
• Provide a mechanism for defining the
relationship among different words and for
the Semantic Web, relationships among
different resources

Ontologies (cont)
• Consist of:
Taxonomies
• “An organized set of terms.” (McComb, 204)
• A classification and a tree (Daconta et al., 2003)
• Hierarchal, tree-like structures similar to
organizational charts
• Example
Sets of inference rules
• Should be used to organize semantics, but
not knowledge
Next

Taxonomy Example
Return

Agents
• Also known as software agents
• Provide automation services
• Should not be designed to replace
humans or to make decisions
• Examples: Web spiders and crawlers

Supplemental Components of
the Semantic Web
• Uniform Resource Identifiers (URIs)
Provide a mechanism for identifying available
resources
• Web services
Allow computer applications to communicate
directly with each other over the Internet
• Inference rules
Define the relationships and rules between
data

Supplemental Components of
the Semantic Web (cont)
• Service discovery
Allows applications to find ontologies and agents
• Semantic aware applications
Applications that can make use of semantic
information
• Security and trust
• XML schema
Define the structure of XML documents
Standardizes the communication between systems
• RDF schema or OWL
Can be used to define the language used in ontologies
and RDFs

Why the Semantic Web is Needed
• The current Web remains largely
unstructured (e.g., company)
• Large amounts of information remain
unavailable

Uses of the Semantic Web
• Improve e-business processes
• Improve business-to-business (B2B)
communication
• “assist human users in their day-to-day online
activities” (Antoniou & van Harmelen, 2004)
• “build knowledge and understanding from raw data”
(Daconta et al., 2003)
Improve knowledge management
Improve information retrieval
Automate tasking
Integrate data
Maximize customer value and profits

Implementing the Semantic Web
• Convert data to XML format according to defined
XML schemas
• Expose applications as Web services
• Build ontologies that specify semantic
meanings and the relationships between
data
• Create agents that make use of the semantic
data, automate search processes, and
automate other business processes

Issues Concerned with
Implementing the Semantic Web
• Cost
• Security
• Nonstandard technology issues
• Semantic precision

Examples
• http://www.foaf-project.org/
• http://www.cs.umd.edu/users/hendler/
• http://www.cs.umd.edu/projects/plus/SHO
E/cs.html
• http://www.daml.ri.cmu.edu/Cal/
• http://www.semanticwebsearch.com/refere
nce.rsp

Conclusion
• What is the Semantic Web
• Background
• Components of the Semantic Web
• Why the Semantic Web is needed
• Uses of the Semantic Web
• Implementing the Semantic Web
• Issues concerned with implementing the
Semantic Web
• Examples
Questions

References
• Antoniou, G., & van Harmelen, F. (2004). A semantic Web primer.
Cambridge, MA: The MIT press.
• Athauda, R. I. (2000). Integration and querying of heterogeneous,
autonomous, distributed database systems (Vol. 61/06, pp. 3126):
Florida International University.
• Berners-Lee, T., Hendler, J., & Lassila, O. (2001). The Semantic Web.
Scientific American, 284(5), 34-43.
• Carey, P., & Kemper, M. (2003). New perspectives on creating Web
pages with HTML and Dynamic HTML (2nd ed.). Boston: Course
Technology.
• Daconta, M. C., Obrst, L. J., & Smith, K. T. (2003). The Semantic Web:
A guide to the future of XML, Web services, and knowledge
management. Indianapolis, IN: Wiley Publishing, Inc.
• Ewalt, D. M. (2002, October 14). Semantic Web. InformationWeek, 35-
44.
• Galitz, W. O. (2002). The essential guide to user interface design. New
York: John Wiley & Sons, Inc.

References
• Gould, M. (1996). Rules in the virtual society. International Review of
Law, Computers & Technology, 10(2), 199-218.
• Kalakota, R., & Robinson, M. (2001). e-Business 2.0: Roadmap for
success. Upper Saddle River, NJ: Addison-Wesley.
• Lexico Publishing Group, L. (2004). Inference. Retrieved December 7,
2004, from http://dictionary.reference.com/searchq=inference
• McComb, D. (2004). Semantics in business systems: The savvy
manager's guide. San Francisco, CA: Morgan Kaufmann Publishers.
• Tiwana, A. (2002). The knowledge management toolkit. Upper Saddle
River, NJ: Prentice Hall PTR.
• Warren, P. (2003). The next steps for the WWW: Putting meaning into
the Web. Computing & Control Engineering, 14(2), 27-31.
• Young, M. J. (2002). XML step by step (2nd ed.). Redmond, WA:
Microsoft Press.