Semantic Web Past Present Future Ying Ding SLIS

Semantic Web: Past, Present, Future Ying Ding SLIS, IU

What is the Semantic Web?

What is the Semantic Web? Scientific American Article 2001 l “An extension of the current Web in which information is given well-defined meaning, better enabling computers and people to work in cooperation. ” l Sir Tim Berners-Lee et al. , Scientific American, 2001: tinyurl. com/i 59 p l “…allowing the Web to reach its full potential…” with far-reaching consequences l “The next generation of the Web” 3

Semantic Web l Tim Berners-Lee has a vision of a Semantic Web which has l l machine-understandable semantics of its information, and millions of (small) specialized reasoning services that provide support in automated task achievement based on the accessible information

The Semantic Web in Essence l The word “semantic” stands for “the meaning of”: l l The Beatles were a popular band from Liverpool; Lennon was a member of the Beatles; "We Can Work It Out" was recorded by the Beatles The Semantic Web is a Web extension that is able to describe things and their properties and interrelations in a way that computers can process 5

Metadata and Semantics

Ontology l The Semantic Web is essentially based on ontologies l ontologies are formal and consensual specifications of conceptualizations l providing a shared and common understanding of a domain that can be communicated across people and application systems

A Very Simple Ontology Graphical (Directed Labeled Graph): Device owns Person is-a Audio-Device Symbolic (triples): Person owns Device Audio-Device is-a Device has Volume. Control Audio-Device has Volume. Control Ontologies describe concepts and their relations. Exercise: Describe earlier text about the Beatles using any kind of (graphical or symbolic) ontology.

Semantic Web - Language Layering http: //www. w 3. org/2007/03/layer. Cake. png

What is the Semantic Web for? l l Integrating - trying to solve the problem of data and service integration Searching - providing better communication between humans and computers by adding machine-processable semantics to data.

Semantic Integration l Bottom-up approach: Building different domain ontologies for better data integration and communication within those domains: l Papi. Net. org: Vocabulary for Paper Industry l BPMI. org: Vocabulary for exchanging Business Process Models l XML-HR: Vocabularies for Human Resources (HR) l DMTF: Distributed Management Task Force: Vocabularies for managing enterprises

Semantic Integration CRM Marketing Sales Semantic Integration Semantics Syntax Software Hardware Plumbing (networking: tcp/ip, corba, rmi, http, soap)

Semantic Differences: Example Marketing Sales ? Person P# Name FName DName BDate LSale 76798 de Bruijn Jos de Bruijn 1979 -06 -23 2001 -04 -07 1. 2. 3. 4. Customer Syntax Semantics distinct equivalent distinct Cust. Nr Name Surname Initials BDate 43526 Jos Debruijn J 1979 -06 -23

Information Integration Patterns (1): Ad Hoc Integration O(n 2) Sales App 4 Marketing App 5 CRM

Information Integration Patterns (2): Global Integration O(n) CRM App 4 App 5 Global Model Marketing Sales Not a silver bullet!

Exercise

Semantic Searching

Semantic Searching

Semantic Web: Past

WWW – Web 1. 0

The Earlier (Syntactic / Structural) Web

Was the Web Meant to be More?

How to Realize Tim Berners-Lee’s Vision l Another chance for “Artificial Intelligence (AI)”? l l l Knowledge Representation (representing semantics) Logic Programming (reasoning semantics) Decisions about background logics for Semantic Web languages: l l RDF: Logic formalized by Patrick Hayes OWL: Description Logic l l DARPA + EU = DAML+OIL (in 2001) RIF (BLD): Horn Logic plus F-logic syntax

Semantic Web: Present

Social Web – Web 2. 0 l l The term Web 2. 0 was made popular by Tim O’Reilly: l http: //www. oreillynet. com/pub/a/oreilly/tim/news/2005/09/30/whatis-web-20. html http: //en. wikipedia. org/wiki/Web_2. 0 l “Web 2. 0 … has … come to refer to what some people describe as a second phase of architecture and application development for the World Wide Web. ” The Web where “ordinary” users can meet, collaborate, and share using social software applications on the Web (tagged content, social bookmarking, AJAX, etc. ) Popular examples include: l Bebo, del. icio. us, digg, Flickr, Google Maps, Skype, Technorati, orkut, 43 Things, Wikipedia, …

Social Networks

A Move from the Web to a “Social Web”

Features / Principles of Web 2. 0 http: //www. oreillynet. com/pub/a/oreilly/tim/news/2 005/09/30/what-is-web-20. html The Web as platform Harnessing collective intelligence Data is the next “Intel Inside” Rich user experience l 1. 2. 3. 4.

Web 2. 0 Meme Cloud

W 3 C SWEO Linking Open Data Project l Project aims to l l l Publish existing open license datasets as linked data on the Web Interlink things between different data sources Develop clients and applications that consume linked data from the Web

Bubbles in May 2007 Over 500 M RDF triples (e. g. , in DBpedia: dp: Galway dp: population 72 K) Around 120 K RDF links between data sources (e. g. , links accessing DBpedia from Musicbrainz)

Bubbles in April 2008 >2 B RDF triples Around 3 M RDF links

Bubbles in July 2009 >4. 7 B RDF triples Around 142 M RDF links

Bio Bubbles

Power of Linked Data rdf: type ying foaf: name foaf: Person foaf: knows dblp: publications foaf: publication Stefan Ying Ding foaf: based_near 72 K dp: population dp: Galway dp: Dublin skos: subject dp: Cities_in_Ireland

What Can LOD Bring? l l l It will lift current document Web to a data Web LOD browsers can let you navigate between different data sources by following RDF links It can drill down to lower-granularity levels of the information l l allowing you for more fine-grained search on the Web making question-answering search on the Web possible meshing up different data through RDF links Making ‘built-on-top’ applications easier

DBTune: Music-related Structured Data http: //dbtune. org

Industry Pick-up

Industry Pick-up l Semantic Technology Conferences – The major industrial series in the Semantic Web area l l l http: //www. semantic-conference. com/ Attendance includes major IT giants (Google, Yahoo, IBM, Oracle, Intel, Vulcan) Radar Networks Company raised $18 M to implement semantics l Twine (a collective semantic knowledge space): http: //www. twine. com/

Semantic Web: Future

Metaweb Social Semantic Information Spaces

1+1>2 l l l Semantic forums Semantic blogs Semantic wikis Semantic social nets Semantic desktop Semantic Web + Social Software

Document Web vs. Data Web l Document Web l l l Glued by hyperlinks Data are HTML pages Query result is HTML pages, which cannot be further processed Data are just interlinked, but not integrated Data access through different APIs l Data Web l l l Social Web + Semantic Web Next Generation Web Document Web Data Web Service Web Glued by RDF links Data are RDF triples Query result is RDF triples which can be easily further processed (e. g. , Web services) Data are interlinked and integrated, and links are typed Data access through a single and standardized access mechanism (maybe it will be called LOD API in the future? )

Will Google 2. 0 be Semantic? l Google could be superseded, says Web inventor: l l Times. Online: http: //technology. timesonline. co. uk/tol/news/tech_ and_web/article 3532832. ece Google 2. 0 embraces the Semantic Web l Government Computer News: http: //www. gcn. com/online/vol 1_no 1/442901. html#