1. Introduction to Linked Data Juan F. Sequeda Semantic Technology Conference June 2011

2. What is the Semantic Web?

3. What is the Semantic Web?

4. Internet != Web

6. What is the Web? “… the Web, is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images […] and navigate between them via hyperlinks” http://en.wikipedia.org/wiki/World_Wide_Web

7. Current Web = internet + links + docs

8. History of the Web Created by Tim Berners-Lee at CERN in 1989 Mosaic browser in 1993 W3C created in 1994 Exponential growth mid 90s Amazon, Ebay – 1995 Search engines – Google 1998 Dot-com boom 1997 – 2001 Web 2.0 – blogs, Facebook, Twitter, etc

9. What is the problem?

10. WHAT’S THE WEATHER IN SAN FRANCISCO TODAY?

14. What is the problem? The web is full of documents We aren’t always interested in documents We are interested in THINGS These THINGS might be in documents We can read a HTML document rendered in a browser and find what we are searching for This is hard for computers. Computers have to guess (even though they are pretty good at it)

15. The Web is a Data Shredder Structured Data Unstructured Data Thanks Martin Hepp

16. What would we like? Make it easy for computers/software to find THINGS Do you SEARCH or do you FIND?

17. Search for Football Players who went to the University of Texas at Austin, played for the Dallas Cowboys as Cornerback

21. Why can’t we just FIND it…

24. Guess how I FOUND out?

25. On a Semantic Web Besides publishing documents on the web which computers can’t understand easily Let’s publish on the web something that computers can understand DATA

26. The Semantic Web is a web of linked data The current web is a web of linked documents

27. But wait… doesn’t the web already have data?

28. Current Data on the Web Relational Databases APIs XML CSV XLS … Can’t computers and applications already consume that data on the web?

29. Yes! But it is all in different formats and data models!

30. This makes it hard to integrate data

31. The data in different data sources aren’t linked

32. For example, how do I know that the Juan Sequeda in Facebook is the same as Juan Sequeda in Twitter

33. Or if I create a mashup from different services, I have to learn different APIs and I get different formats of data back

34. Data is Siloed

35. Wouldn’t it be great if we had a standard way of publishing data on the Web?

36. We have a standardized way of publishing documents on the web, right? HTML

37. Then why can’t we have a standard way of publishing data on the Web?

38. Good question! And the answer is YES. There is! RDF

39. Resource Description Framework (RDF) A data model A way to model data i.e. Relational databases use relational data model RDF is a triple data model Labeled Graph Subject, Predicate, Object <Juan> <was born in> <California> <California> <is part of> <the USA> <Juan> <has hobby> <Salsa dancing>

40. RDF can be serialized in different ways RDF/XML RDFa (RDF in HTML) N3 Turtle JSON

41. So does that mean that I have to publish my data in RDF now?

42. You don’t have to… but we would like you to 

43. An example

44. Document on the Web

45. Databases back up documents THINGS have PROPERTIES: A Book as a Title, an author, … This is a THING: A book title “Programming the Semantic Web” by Toby Segaran, …

46. Lets represent the data in RDF Programming the Semantic Web title author book Toby Segaran isbn 978-0-596-15381-6 publisher name Publisher O’Reilly

47. Remember that we are on the web Everything on the web is identified by a URI

48. And now let’s link the data to other data Programming the Semantic Web title author http://…/isbn978 Toby Segaran isbn 978-0-596-15381-6 publisher name http://…/publisher1 O’Reilly

49. And now consider the data from Revyu.com hasReview http://…/review1 http://…/isbn978 description reviewer Awesome Book http://…/reviewer name Juan Sequeda

50. Let’s start to link data hasReview http://…/review1 http://…/isbn978 Programming the Semantic Web title description sameAs hasReviewer Awesome Book author http://…/isbn978 Toby Segaran http://…/reviewer name isbn 978-0-596-15381-6 Juan Sequeda publisher name http://…/publisher1 O’Reilly

51. Juan Sequeda publishes data too http://juansequeda.com/id http://dbpedia.org/Austin livesIn name Juan Sequeda

52. Let’s link more data hasReview http://…/review1 http://…/isbn978 description hasReviewer Awesome Book http://…/reviewer name Juan Sequeda sameAs http://juansequeda.com/id http://dbpedia.org/Austin livesIn name Juan Sequeda

53. And more hasReview http://…/review1 http://…/isbn978 Programming the Semantic Web title description sameAs hasReviewer Awesome Book author http://…/isbn978 Toby Segaran http://…/reviewer name isbn 978-0-596-15381-6 Juan Sequeda publisher sameAs http://…/publisher1 name O’Reilly http://juansequeda.com/id http://dbpedia.org/Austin livesIn name Juan Sequeda

54. Data on the Web that is in RDF and is linked to other RDF data is LINKED DATA

55. Linked Data Principles Use URIs as names for things Use HTTP URIs so that people can look up (dereference) those names. When someone looks up a URI, provide useful information. Include links to other URIs so that they can discover more things.

56. Linked Data makes the web appear as ONEGIANTHUGEGLOBALDATABASE!

57. I can query a database with SQL. Is there a way to query Linked Data with a query language?

58. Yes! There is actually a standardize language for that SPARQL

59. FIND all the reviews on the book “Programming the Semantic Web” by people who live in Austin

60. SELECT ?review ?comment WHERE { isbn:978 ex:hasReview ?review . ?review ex:description ?comment . ?review ex:hasReviewer ?person . ?person ex:livesdbpedia:Austin . }

61. SELECT ?review ?comment WHERE { isbn:978 ex:hasReview ?review . ?review ex:description ?comment . ?review ex:hasReviewer ?person . ?person ex:livesdbpedia:Austin . } hasReview http://…/review1 http://…/isbn978 Programming the Semantic Web title description sameAs hasReviewer Awesome Book author http://…/isbn978 Toby Segaran http://…/reviewer name isbn 978-0-596-15381-6 Juan Sequeda publisher sameAs name http://…/publisher1 O’Reilly http://juansequeda.com http://dbpedia.org/Austin livesIn name Juan Sequeda

62. This looks cool, but let’s be realistic. What is the incentive to publish Linked Data?

63. What was your incentive to publish an HTML page in 1990?

64. 1) Share data in documents2) Because you neighbor was doing it… later on …3) Marketing, Advertising, SEO

65. So why should we publish Linked Data in 2011?

66. 1) Share data as data2) Because you neighbor is doing it…3) (Semantic) SEO ++

67. Linked Data Publishers UK Government US Government BBC Open Calais – Thomson Reuters Freebase/Google NY Times Best Buy CNET Dbpedia Overstock.com O’Reilly Media …

68. May 2007

69. Oct 2007

70. Nov 2007

71. Feb 2008

72. Mar 2008

73. Sept 2008

74. Mar 2009 (1)

75. Mar 2009 (2)

76. July 2009

77. September 2010

78. June 2011 YOU GET THE PICTURE ITS BIG and getting BIGGER and BIGGER

79. QUESTIONS?