Introduction to the Semantic Web Mauricio Espinoza
Acknowledgements: Asunción Gómez-Pérez, Oscar Corcho, Jesús Barrasa, Angel López Cima, Oscar Muñoz, Jose Angel Ramos Gargantilla, María del Carmen Suárez de Figueroa, Boris Villazón, Mariano Fernández López, Luis Vilches, Carlos Ruíz Moreno
Work distributed under the license Creative Commons AttributionNoncommercial-Share Alike 3.0
Overview • The Web 1.0 and Web 2.0 • The Semantic Web,
Overview • The Web 1.0 and Web 2.0 • The Semantic Web,
The beginning: Web 1.0 WWW HTTP URI
Web2.0 basic sites and services
Web1.0 vs Web2.0
• Cooperation • Dynamicity • Decentralised change • Heterogeneity • Multimedia content
Overview • The Web 1.0 and Web 2.0 • The Semantic Web
(Syntactic) Web Limitations Resource href
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A place where computers do the presentation (easy) and people do the linking and interpreting (hard). Why not get computers to do more of the hard work?
(Syntactic) Web Limitations
• Let's go to the cinema! • • •
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Mauricio, 20:00. . . Let's go to see The Hobbit now!" Need to find out which cinema plays the movie tonight, e.g. on http://www.google.no/movies Need to find out where those cinemas are Need to find out which of those cinemas we can reach on time using public transport, e.g. on http://www.ruter.no/ Web user needs to combine information from different sites Essentially a database join!
The Solution?
• Wait for Google to produce a Cinema+Public Transport mashup?
• But what about • Real estate + public transport? • schedules and pricing + weather information?
• Can hardly wait for a separate mashup for each useful combination!
A Web of Data!
Imagine. . . • All those websites publish their information in a machine-readable format. • The data published by different sources is linked • Enough domain knowledge is available to machines to make use of the information • User-agents can find and combine published information in appropriate ways to answer the user's information needs.
What’s the Problem? • Typical web page markup consists of: • Rendering information (e.g., font size and colour) • Hyper-links to related content
• Semantic content is accessible to humans but not (easily) to computers…
Information we can see… Universidad de Cuenca Organización Universitaria Alumnos Investigación Eventos y actividades… (en la universidad/fuera…?)
Noticias Tipos de personas a los que va dirigido Alumnos Profesores Personal de Administración y Servicios …
Information a machine can see…
WWW2002 The eleventh international world wide webcon Sheraton waikiki hotel Honolulu, hawaii, USA 7-11 may 2002 1 location 5 days learn interact Registered participants coming from australia, canada, chile denmark, france, germany, ghana, hong kong, india, ireland, italy, japan, malta, new zealand, the netherlands, norway, singapore, switzerland, the united kingdom, the united states, vietnam, zaire Register now On the 7th May Honolulu will provide the backdrop of the eleventh international world wide web conference This prestigious event Speakers confirmed Tim berners-lee Tim is the well known inventor of the Web,…
Solution: XML markup with “meaningful” tags?
<name>WWW2002 The eleventh international world wide webcon</name> <date>7-11 may 2002</date> <location>Sheraton waikiki hotel Honolulu, hawaii, USA</location> <introduction>Register now On the 7th May Honolulu will provide the backdrop of the eleventh international world wide web conference This prestigious event Speakers confirmed</introduction> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <registration>Registered participants coming from australia, canada, chile denmark, france, germany, ghana, hong kong, india, ireland, italy, japan, malta, new zealand, the netherlands, norway, singapore, switzerland, the united kingdom, the united states, vietnam, zaire<registration>
But What About…?
<conf>WWW2002 The eleventh international world wide webcon</conf> <date>7-11 may 2002</date> <place>Sheraton waikiki hotel Honolulu, hawaii, USA</place> <introduction>Register now On the 7th May Honolulu will provide the backdrop of the eleventh international world wide web conference This prestigious event Speakers confirmed</introduction> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <registration>Registered participants coming from australia, canada, chile denmark, france, germany, ghana, hong kong, india, ireland, italy, japan, malta, new zealand, the netherlands, norway, singapore, switzerland, the united kingdom, the united states, vietnam, zaire<registration>
Still the Machine only sees…
<conf>WWW2002 The eleventh international world wide webcon<conf> <date>7-11 may 2002</date> <place>Sheraton waikiki hotel Honolulu, hawaii, USA<place> <introduction>Register now On the 7th May Honolulu will provide the backdrop of the eleventh international world wide web conference This prestigious event Speakers confirmed</introduction> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <speaker>Tim berners-lee <bio>Tim is the well known inventor of the Web,</bio> </speaker> <registration>Registered participants coming from australia, canada, chile denmark, france, germany, ghana, hong kong, india, ireland, italy, japan, malta, new zealand, the netherlands, norway, singapore, switzerland, the united kingdom, the united states, vietnam,
What is the Semantic Web?
• An extension of the current Web… • … where information and services are given well-defined and explicitly represented meaning, … • … so that it can be shared and used by humans and machines, ... • ... better enabling them to work in cooperation
• How? • Promoting information exchange by tagging web content with machine processable descriptions of its meaning. • And technologies and infrastructure to do this
Need to Add “Semantics” • Agreement on the meaning of annotations • •
Shared understanding of a domain of interest Formal and machine manipulable model of a domain of interest
• An ontology is an engineering artifact, which provides: • •
A vocabulary of terms A set of explicit assumptions regarding the intended meaning of the vocabulary. • Almost always including concepts and their classification • Almost always including properties between concepts
The “Home" of the Semantic Web • See the W3C pages for the Semantic Web effort: • https://www.w3.org/2013/data/
• For standards (RDF, OWL, SPARQL, etc.), see: • http://www.w3.org/2001/sw/wiki/Main_Page