1 The Semantic Web Jonathan Jackson GCUU Master’s Seminar Spring 2005

2 Agenda Background Information Background Information Story Story Problem Statement Problem Statement What is the Semantic Web What is the Semantic Web What can the Semantic Web do What can the Semantic Web do What’s out there now What’s out there now Conclusion Conclusion

3 Background The World Wide Web is one of the leading sources of information The World Wide Web is one of the leading sources of information Not all information on the WWW is accurate or important to a given search Not all information on the WWW is accurate or important to a given search Searching the WWW for information can be long and frustrating Searching the WWW for information can be long and frustrating It would be nice to have a way of automating this It would be nice to have a way of automating this

4 The Current Internet Web Pages contain information know as metadata Web Pages contain information know as metadata This information provides a description of the content of the page This information provides a description of the content of the page Metadata is normally used by search engines Metadata is normally used by search engines

5 The Current Internet Not all pages contain metadata Not all pages contain metadata Data that describes pages has no set format Data that describes pages has no set format Descriptions of content have no meaning other than what people and understand intuitively Descriptions of content have no meaning other than what people and understand intuitively

6 Story Would like to make an appointment with a dentist Would like to make an appointment with a dentist Would like a program that can find a dentist within 10 miles of office Would like a program that can find a dentist within 10 miles of office Make an appointment as soon as possible within one of the available time periods Make an appointment as soon as possible within one of the available time periods

7 Story Programs would have a hard time searching the WWW for information and providing these types of services Programs would have a hard time searching the WWW for information and providing these types of services This is due to the disorganization of information This is due to the disorganization of information

8 Problem Statement Is there a way to formalize information on the WWW Is there a way to formalize information on the WWW Would a developer be able to provide meaning to descriptions on web pages Would a developer be able to provide meaning to descriptions on web pages Could this be done in a way that would make automation easy Could this be done in a way that would make automation easy

9 What is the Semantic Web A framework for organizing information in a formal matter A framework for organizing information in a formal matter This framework provides structure to information along with the ability to make inferences based on the data This framework provides structure to information along with the ability to make inferences based on the data Using a formal framework allows programs to extract and analyze information more efficiently Using a formal framework allows programs to extract and analyze information more efficiently

10 The Semantic Web RDF - provides syntax RDF - provides syntax Ontologies - analysis of information Ontologies - analysis of information Agents - programs created for Semantic Web use Agents - programs created for Semantic Web use

11 Resource Descriptive Framework (RDF) Provides syntax for the Semantic Web Provides syntax for the Semantic Web Object-oriented system Object-oriented system Made up of sets of triples Made up of sets of triples Each triple consists of a subject, object, predicate Each triple consists of a subject, object, predicate

12 RDF Examples Animal rdf:type rdf:Class Human rdfs:subClassOf Animal Dog rdfs:subClassOf Animal Duck rdfs:subClassOf Animal

13 Example Steve rdf:type Human Daffy rdf:type Duck Pluto rdf:type Dog

14 Example We can also add relationships between objects on a page We can also add relationships between objects on a page owns rdf:type rdf:Property Steve owns Pluto

15 RDF Use the RDF to describe the information that is read by people Use the RDF to describe the information that is read by people The structure provided by RDF is similar to the structure that the reader creates in his head The structure provided by RDF is similar to the structure that the reader creates in his head i.e., On Steve’s page, we know that Steve is a person and he owns a dog named Pluto i.e., On Steve’s page, we know that Steve is a person and he owns a dog named Pluto

16 Ontologies Give meaning and express relationships between words Give meaning and express relationships between words Ex. Want to find a dentist with the “zip code” Ex. Want to find a dentist with the “zip code” 11575

17 Ontologies Can create inferences about the data Can create inferences about the data Ex. Want to find the names of secondary relatives of a student Ex. Want to find the names of secondary relatives of a student Problem: Agents can still become confused Problem: Agents can still become confused

18 Ontologies:Problems People can use different ontologies for the same purposes People can use different ontologies for the same purposes Can still have ambiguity of meaning Can still have ambiguity of meaning How does one give meaning to words How does one give meaning to words Easy for restricted domains but very difficult of larger domains Easy for restricted domains but very difficult of larger domains

19 What’s Out There Now? Retsina Retsina Calendar/Organizer agent Calendar/Organizer agent Uses Semantic Web and M$ Outlook Uses Semantic Web and M$ Outlook Allows users to view schedules, book meetings, and Allows users to view schedules, book meetings, and

20 What’s Out There Now MusicBrainz MusicBrainz Database-driven website that stores information about music artists and their work Database-driven website that stores information about music artists and their work Semantic Web version of CDDB (Gracenote) Semantic Web version of CDDB (Gracenote)

21 Conclusion The Semantic Web is a promising idea The Semantic Web is a promising idea The Semantic Web framework does not solve problems of misinformation The Semantic Web framework does not solve problems of misinformation The problems involves with ontologies are similar to those in AI and do not look to be solved any time soon The problems involves with ontologies are similar to those in AI and do not look to be solved any time soon Agents will work well in small domains but will suffer as generality increases Agents will work well in small domains but will suffer as generality increases