Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Ist16-03 An Introduction to the Semantic Web

894 views

Published on

The third lecture of the course I'm giving on "Interoperability and Semantic Technologies" at Politecnico di Milano in the academic year 2015-16. It presents an introduction to the Semantic Web taking a brief walk through in this 15 years of research, standardisation and industrial uptake.

Published in: Internet
  • Be the first to comment

Ist16-03 An Introduction to the Semantic Web

  1. 1. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Interoperability and Semantic Technologies 2015-16 An Introduction to the Semantic Web Emanuele Della Valle DEIB - Politecnico di Milano http://emanueledellavalle.org - @manudellavalle
  2. 2. E. Della Valle – http://emanueledellavalle.org - @manudellavalle This work is licensed under the Creative Commons Attribution 3.0 Unported License. Your are free: to Share — to copy, distribute and transmit the work to Remix — to adapt the work Under the following conditions Attribution — You must attribute the work by inserting “by E. Della Valle – http://emanueledellavalle.org - @manudellavalle” at the end of each reused slide To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ Share, Remix, Reuse — Legally 2
  3. 3. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction The Web Today 3 Large number of integrations - ad hoc - pair-wise Too much information to browse, need for searching and mashing up automatically Each site is “understandable” for us Computers don’t “understand” much ? Search & Mash-up Engine 010 0 1 1 0 0 1101 10100 10 0010 01 101 101 01 110 1 10 1 10 0 1 1 0 1 0 1 0 0 1 1 0 1 1 1 10 0 1 101 0 1 Millions of Applications
  4. 4. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction The Problem: “Semantic Gap” 4 Sensor Data Semantic Gap Symbolic Description
  5. 5. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction “Understanding” Means Bridging the Gap 5 understanding Sensor Data Symbolic Description
  6. 6. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Do We Really Know What “Understanding” means? 6 [ source http://www.thefarside.com/ ]
  7. 7. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Two ways for computer to “understand” 7 Smart Data Smart Machine
  8. 8. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Working examples found on the Web Image Processing retrievr: find by sketching http://labs.systemone.at/retrievr/ Audio Processing midomi: find by singing http://www.midomi.com/ […] Natural Language Processing semantic proxy: http://semanticproxy.opencalais.com/about.html Introduction Smart Machines 8 Sensor Data Symbolic Description Image Processing Audio Processing NaturalLanguage Processing […]
  9. 9. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Natural Language Processing (NLP) meets Image Processing (IP) NLP: What does your eye see? IP : I see a sea NLP: You see a “c”? IP : Yes, what else could it be? Introduction Smart Machines alone cannot bridge the gap … 9 [Source NLP Related Entertainment http://www.cl.cam.ac.uk/Research/NL/amusement.html] Sensor Data Symbolic Description Image Processing Natural Language Processing sea “c” Semantic Gap
  10. 10. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Natural Language Processing (NLP) meets Image Processing (IP) NLP: What does your eye see? IP : I see a wordnet:word-sea NLP: mmm, I see a wordnet:word-c IP : I believe we have different understanding of the world … NLP: So do I Introduction … smart data are need 10 Sensor Data Symbolic Description Image Processing Natural Language Processing sea “c” smart data The Semantic Web offers a set of standards that lowers the barriers to employ smart data at Web scale
  11. 11. E. Della Valle – http://emanueledellavalle.org - @manudellavalle What we say to Web agents  " For more information visit <a href=“http://www.ex.org”> my company </a> Web site. . .” What they “hear”  " blah blah blah blah blah <a href=“http://www.ex.org”> blah blah blah </a> blah blah. . .”  Jet this is enought to train them to achive tasks for us Introduction What a machine “understands” of the Web 11 [ source http://www.thefarside.com/ ]
  12. 12. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Understanding that [page1] links [page2]  page2 is interesting Google is able to rank results! “The heart of our software is PageRank™, a system for ranking web pages […] (that) relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value.” http://www.google.com/technology/ Introduction What does Google “understand”? 12
  13. 13. E. Della Valle – http://emanueledellavalle.org - @manudellavalle “The Semantic Web is not a separate Web, but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.” “The Semantic Web”, Scientific American Magazine, Maggio 2001 http://www.sciam.com/article.cfm?articleID=00048144-10D2-1C70-84A9809EC588EF21 Key concepts • an extension of the current Web • in which information is given well-defined meaning • better enabling computers and people to work in cooperation. • Both for computers and people Introduction The Semantic Web 1/4 13
  14. 14. E. Della Valle – http://emanueledellavalle.org - @manudellavalle “The Semantic Web is not a separate Web, but an extension of the current one […] ” Introduction The Semantic Web 2/4 14 Web 1.0 The Web Today
  15. 15. E. Della Valle – http://emanueledellavalle.org - @manudellavalle “The Semantic Web […] , in which information is given well- defined meaning […]” Introduction The Semantic Web 3/4 15 Human understandable but “only” machine-readable Human and machine “understandable” ? Web 1.0 Semantic Web
  16. 16. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction The Semantic Web 4/4 16 Semantic Web META METAMETA META META META META META META META Fewer Integration - standard - multi-lateral […] better enabling computers and people to work in cooperation. Even More Applications Easier to understand for people More “understandable” for computers Semantic Mash-ups & Search
  17. 17. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Linked Data Standards 17 View the full talk at http://www.ted.com/talks/view/id/484 !
  18. 18. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Goal: extend the Web with data commons by publishing open data sets using Semantic Web techs Introduction Linking Open Data Project Visit http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData !
  19. 19. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Example: BIO2RDF 19 Peter Ansell, Model and prototype for querying multiple linked scientific datasets, Future Generation Computer Systems, Volume 27, Issue 3, March 2011, Pages 329-333
  20. 20. E. Della Valle – http://emanueledellavalle.org - @manudellavalle • is an effort to add a spatial dimension to the Semantic Web. • uses the information collected by the OpenStreetMap project • makes it available as an RDF knowledge base according to the Linked Data principles. • interlinks this data with other knowledge bases in the Linking Open Data initiative. Introduction Example: LinkedGeoData 20
  21. 21. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction data.gov and data.gov.uk 21
  22. 22. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction https://open-data.europa.eu/en/data
  23. 23. E. Della Valle – http://emanueledellavalle.org - @manudellavalle • Who: Richard MacManus • When: April 15th, 2010 • Context: Modigliani’s painting are scattered all other the world • The challenge: If all museums would have published their collections as linked data, will it be possible to know the locations of all the original paintings of Modigliani? • http://readwrite.com/2010/04/15/the_modigliani_test_semantic_web_tippi ng_point Introduction The Modigliani test for Linked Data
  24. 24. E. Della Valle – http://emanueledellavalle.org - @manudellavalle <?xml version="1.0" encoding="utf-8"?> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:owl = "http://www.w3.org/2002/07/owl#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:foaf = "http://xmlns.com/foaf/0.1/" xmlns:rel = "http://www.perceive.net/schemas/relationship/" xmlns:mo = "http://purl.org/ontology/mo/" xmlns:rev = "http://purl.org/stuff/rev#" > <rdf:Description rdf:about="/music/artists/a3cb23fc-acd3-4ce0-8f36- 1e5aa6a18432.rdf"> <rdfs:label>Description of the artist U2</rdfs:label> <foaf:primaryTopic rdf:resource="/music/artists/a3cb23fc-acd3-4ce0-8f36- 1e5aa6a18432#artist"/> </rdf:Description> <mo:MusicGroup rdf:about="/music/artists/a3cb23fc-acd3-4ce0-8f36- 1e5aa6a18432#artist"> <foaf:name>U2</foaf:name> <owl:sameAs rdf:resource="http://dbpedia.org/resource/U2" /> <foaf:page rdf:resource="/music/artists/a3cb23fc-acd3-4ce0-8f36- 1e5aa6a18432.html" /> <mo:musicbrainz rdf:resource="http://musicbrainz.org/artist/a3cb23fc-acd3- 4ce0-8f36-1e5aa6a18432.html" /> <mo:homepage rdf:resource="http://www.u2.com/" /> <mo:fanpage rdf:resource="http://www.atu2.com/" /> <mo:wikipedia rdf:resource="http://en.wikipedia.org/wiki/U2" /> <mo:imdb rdf:resource="http://www.imdb.com/name/nm1277752/" /> <mo:myspace rdf:resource="http://www.myspace.com/u2" /> <mo:member rdf:resource="/music/artists/7f347782-eb14-40c3-98e2- 17b6e1bfe56c#artist" /> <mo:member rdf:resource="/music/artists/1f52af22-0207-40ac-9a15- e5052bb670c2#artist" /> Introduction Example: BBC’s Artist as Linked Data 24 HTML: http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432 RDF : http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.rdf DISCONTINUED
  25. 25. E. Della Valle – http://emanueledellavalle.org - @manudellavalle The Results of Modigliani test for Linked Data • Who: Atanas Kiryakov (Ontotext AD) • When: April 25th, 2010 • How: http://factforge.net/ a “reason-able” view to the web of data • Results: http://bit.ly/ModiglianiTest http://readwrite.com/2010/04/25/the_modigliani_test_for_linked_data Introduction The Modigliani test for Linked Data
  26. 26. E. Della Valle – http://emanueledellavalle.org - @manudellavalle •Since Fall 2009 •450.000 products •Using RDFa (= RDF embedded in HTML) •Pages with RDFa higher in Google ranking •BestBuy claims 30% more traffic! •Yahoo reports 15% higher click- through rat Introduction Example: Best Buy
  27. 27. E. Della Valle – http://emanueledellavalle.org - @manudellavalle © 2012 Politecnico di Milano, Emanuele Della Valle Introduction Example: Best Buy <div rel="v:hasReview"> <span property="v:rating" datatype="xsd:string"> 4.8</span> of <span property="v:best">5</span> <div rel="v:hasReview"> <span property="v:rating" datatype="xsd:string"> 4.8</span> of <span property="v:best">5</span> RDFa
  28. 28. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Google for Nikon+12.3-Megapixel+Digital+SLR+Camera https://www.google.com/search?q=Nikon+12.3-Megapixel+Digital+SLR+Camera Introduction Example: Best Buy en Sponsored Links
  29. 29. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Use RDFa with some FB specific vocabulary og:title - The title of your object, e.g., "The Rock". og:type - The type of your object, e.g., "movie". og:image - An image URL og:url - The permanent ID of your object og:description - A one to two sentence description of your object. og:site_name - If your object is part of a larger web site, the name which should be displayed for the overall site. e.g., "IMDb". Introduction Example: Facebook Open Graph http://ogp.me/
  30. 30. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Open Graph Usage Statistics 15 millions sites are using Open Graph! 39% of the top 10,000 sites Introduction Example: Facebook Open Graph [Source: http://trends.builtwith.com/docinfo/Open-Graph-Protocol] % 40 30 20 2010 2011 2012 2013 2014 2015
  31. 31. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Industrial uptake of Semantic markup 2009/2010 winter-2014 147.871.837 urls 620.151.400 urls microformats 80% rdfa+microdata 80% [Source: http://webdatacommons.org/structureddata/index.html#results-2013-1 ] 80% 20% 10%
  32. 32. E. Della Valle – http://emanueledellavalle.org - @manudellavalle RDFa, microformats and "rich snippet" on Google trends Take home message: data formats matter, but data usage matters even more! Introduction Usage matters! microformats RDFa Rich snippet
  33. 33. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Usage matters! Yahoo! Search Monkey [source https://developer.yahoo.com/searchmonkey/siteowner.html ]
  34. 34. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Usage matters! Google structured data [source https://developers.google.com/structured-data/rich-snippets/ ]
  35. 35. E. Della Valle – http://emanueledellavalle.org - @manudellavalle • Schema.org • an initiative launched on 2 June 2011 by Bing, Google and Yahoo! • to “create and support a common set of schemas for structured data markup on web pages.” • Like microformats it is a collection of vocabularies, but they are organized in a broad type hierarchy (like RDF-Schema) • See http://schema.org/docs/full.html • Initially schema.org introduced yet another type of semantic markup (i.e., microdata), but it stepped back and it now recommends either microdata or RDFa • Tools are available: http://schema.rdfs.org/tools.html Introduction schema.org enriched pages//35
  36. 36. E. Della Valle – http://emanueledellavalle.org - @manudellavalle There are around 1200 types in the hierarchy [Sourcehttp://blog.schema.org/2015/11/schemaorg-whats-new.html] Introduction schema.org
  37. 37. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Beyond rich snippet, into the Knowledge Graph Introduction schema.org
  38. 38. E. Della Valle – http://emanueledellavalle.org - @manudellavalle Introduction Semantic Web “layer cake” 38 Standardized Under Investigation Already Possible [ source http://www.w3.org/2007/03/layerCake.png ]

×