Presentation given at Barcamp Chiang Mai 4 on the basics of Semantic Web. A simple introduction with examples, aimed for those with a little Web development experience. Raises questions about the true identity of Tim Berners-Lee.

1. WTF is Semantic Web?
Miles Worthington

2. Lots of new terms
• Linked Data
• triples
• RDF
• SPARQL
• ontology

3. It’s this guy’s idea
Tim Berners-Lee
• Director of W3C
• Father of the Internet
• Fortune teller

4. One possibility...
==

5. More likely
He drives one of these

6. “I’m telling you Marty, in 2011 the
Semantic Web will be huuuge!!”

7. ?
“I’m telling you Marty, in 2011 the
Semantic Web will be huuuge!!”

8. To find information on
the Web, we use...

9. To find information on
the Web, we use...

10. To find information on
the Web, we use...
and sometimes...

11. is amazing!

12. is amazing!
...at guessing

13. There is a common
problem we all experience
on the Web.

14. Jim’s watching a football match...

15. “...aaand Michael
Jackson has just
scored his fifth
goal of the day!”

16. What?
Five goals?
Michael Jackson?
Who is this guy?

18. Why did I bother...?

20. It’s not even real football!

22. FAIL

24. Search engines can only
do so much with the text
and tags we feed them.

25. Normal Web is about making
information accessible to people.
Semantic Web is about making
information more accessible
to software.

26. (Thank you, Wikipedians)

27. oh well, it'll
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)
(Thank you, Wikipedians)

28. How?
• Give important things identifiers

29. How?
• Give important things identifiers

30. How?
• Give important things identifiers
407161495 ?

31. How?
• Give important things identifiers
407161495 ?
footballer_f285n ?

32. How?
• Give important things identifiers
407161495 ?
footballer_f285n ?
michael_jackson_27 ?

33. How?
Just use the URI
scheme I came up
with years ago!!!

34. How?
Just use the URI
scheme I came up
with years ago!!!
“URI”
Uniform Resource Identifier

35. How?
• Give important things identifiers
407161495 ?
footballer_f285n ?
michael_jackson_27 ?
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

36. URIs and URLs
URI: An identifier
URL: An identifier that points to a document

37. URIs and URLs
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)
 URL
 URI

38. URIs and URLs
http://milesworthington.com/Michael_Jackson
(page does not exist)
 URL
 URI

39. URIs and URLs
Often the same.
But URIs do not always point to
actual pages. Sometimes they are
just names.

40. How?
• Give important things identifiers

41. How?
• Give important things identifiers
• Also give identifiers to the
relationships between things

42. FAIL
Jim

43. FAIL

44. FAIL

45. Traditional Web links
http://jimsblog.com/michael_jackson_match.html
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

46. Semantic Web links
http://jimsblog.com/michael_jackson_match.html
foaf:primaryTopic
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

47. http://jimsblog.com/michael_jackson_match.html
(URI in disguise) foaf:primaryTopic
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

48. http://jimsblog.com/michael_jackson_match.html
http://xmlns.com/foaf/0.1/primaryTopic
http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

49. Jim’s blog post
has a the primary topic of
Michael Jackson the football player

50. Jim’s blog post
has a the primary topic of
Michael Jackson the football player
This is referred to as a “triple”

52. FAIL

53. FAIL

54. MOAR
FAIL METADATA!!

55. MOAR
FAIL METADATA!!

56. This is RDFa,
a practical way
to semanticize the Web

57. Well, it turns out RDFa is
only the tip of the iceberg

58. Remember when we
used <font> tags to
style Web pages?

59. Then some smart people
suggested we separate
structure and presentation...

60. ...and now we have
HTML + CSS

61. Now we have smart people
suggesting we separate
raw, meaningful content and
presentational content

62. Content formatted for software
vs.
Content formatted for humans

63. Linked Data
We need to treat
software the same
way we treat
humans.
Software has
feelings too!

64. Linked Data
Tim is right.
I want to be available
to everyone.
I support Linked Data!

66. DBpedia.org
• The Semantic Web version of Wikipedia
• Contains all the same content from Wikipedia
• Everything is given a URI
• Relationships between things are also expressed with a URI
• Uses Tim’s Linked Data principles

68. MJ’s DBpedia URI
http://dbpedia.org/resource/Michael_Jackson

69. http://dbpedia.org/resource/Michael_Jackson http://dbpedia.org/page/Michael_Jackson

71. http://dbpedia.org/resource/Michael_Jackson http://dbpedia.org/data/Michael_Jackson.xml

79. “Triples”
Michael Jackson
was born in
Gary, Indiana

80. “Triples”
http://dbpedia.org/resource/Michael_Jackson
http://dbpedia.org/ontology/birthPlace
http://dbpedia.org/resource/Gary%2C_Indiana

81. “Triples”
SUBJECT
PREDICATE
OBJECT

82. “Triples”
http://dbpedia.org/resource/Michael_Jackson
http://dbpedia.org/ontology/birthDate
“1958-08-29”

83. Anyone can decide URIs.
You can make your own and
still link to others.

84. http://www.imdb.com/name/nm0001391/
http://www.w3.org/2002/07/owl#sameAs
http://dbpedia.org/resource/Michael_Jackson

85. RDF

86. RDF
• “Resource Description Framework”
• Provides a way to add identifiers (URIs)
to content
• Comes in many flavors

87. RDF
Turtle format
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix ex: <http://example.org/stuff/1.0/> .
<http://www.w3.org/TR/rdf-syntax-grammar>
dc:title "RDF/XML Syntax Specification (Revised)" ;
ex:editor [
ex:fullname "Dave Beckett";
ex:homePage <http://purl.org/net/dajobe/>
].

88. RDF
N-triples format
<http://www.w3.org/2001/sw/RDFCore/ntriples/> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ↵
<http://xmlns.com/foaf/0.1/Document> .
<http://www.w3.org/2001/sw/RDFCore/ntriples/> <http://purl.org/dc/terms/title> "N-Triples"@en-US .
<http://www.w3.org/2001/sw/RDFCore/ntriples/> <http://xmlns.com/foaf/0.1/maker> _:art .
<http://www.w3.org/2001/sw/RDFCore/ntriples/> <http://xmlns.com/foaf/0.1/maker> _:dave .
_:art <http://www.w3.org/1999/02/22-rdf-syntax-ns#> <http://xmlns.com/foaf/0.1/Person> .
_:art <http://xmlns.com/foaf/0.1/name> "Art Barstow".
_:dave <http://www.w3.org/1999/02/22-rdf-syntax-ns#> <http://xmlns.com/foaf/0.1/Person> .
_:dave <http://xmlns.com/foaf/0.1/name> "Dave Beckett".

89. RDF
RDF/XML
<rdf:RDF xmlns="http://xmlns.com/foaf/0.1/"
xmlns:dc="http://purl.org/dc/terms/"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<Document rdf:about="http://www.w3.org/2001/sw/RDFCore/ntriples/">
<dc:title xml:lang="en-US">N-Triples</dc:title>
<maker>
<Person rdf:nodeID="art">
<name>Art Barstow</name>
</Person>
</maker>
<maker>
<Person rdf:nodeID="dave">
<name>Dave Beckett</name>
</Person>
</maker>
</Document>
</rdf:RDF>

90. “Do they really expect us to
create two versions of our
content?”
“One HTML and one RDF?”

91. The Compromise: RDFa
• RDF that lives inside an HTML document
• The “a” stands for attributes
• Uses attributes on HTML tags to hold identifiers

92. The Compromise: RDFa
RDFa
<p xmlns:dc="http://purl.org/dc/elements/1.1/" about="http://www.example.com/books/wikinomics">
In his latest book
<cite property="dc:title">Wikinomics</cite>,
<span property="dc:creator">Don Tapscott</span>
explains deep changes in technology, demographics and business. The book is due to be published in
<span property="dc:date" content="2006-10-01">October 2006</span>.
</p>

95. “That’s still a lot of extra
time and effort...”

96. Drupal 7 publishes basic RDFa
out of the box
Wordpress has plugins to
publish RDFa

97. “But why is any of
this important?”

98. Geek Reason
When most of the Web is published with
RDF/RDFa it becomes a giant database
that we can efficiently query.
... a unified API for the Web

99. Geek Reason
“Find all <type:blog_post>
that are <type:book_review>
for <My_Favorite_Book>
published between <date:one_month_ago>
and <date:now>”

100. Geek Reason
More possibilities for semantic search...

101. Geek Reason
Google, please tell me,
“Which movies did Bruce Willis star in last year?”

102. Geek Reason
It will enable developers to
build tools we can can hardly
conceive of right now.

103. The Real Reason
SEO

104. The Real Reason
SEO
But not just the $$$ part!

105. The Real Reason
SEO
With so much content on the Web,
there’s a real need to
improve our findability

106. Lots of new terms
• Linked Data: connecting data through identifiers
• triples: <MJ> <born in> <Indiana>
• RDF: A way to describe content using identifiers
• SPARQL: A query language for triples
• ontology: A big vocabulary that defines URIs for
classifying things and relationships

107. Thanks!