This document provides an overview of semantic web technologies and graph data models. It discusses how semantic representations can make creating, extending, and combining data easier by representing relationships explicitly and modeling schemas and data as graphs. Graph data models allow for pluggable and portable data through shared meanings facilitated by principles like subject identity, strong and consistent semantics, and open APIs and open data.

1. Drupal Camp
Jamie Taylor

3. What can semantic web
technologies do for you?

4. Tag your content

5. Topic Hubs

6. RDFa Powered Search

7. Data Exploration Widgets

8. Why Semantics?
A Brief History of Data Modeling
Photo CC-BY: http://en.wikipedia.org/wiki/File:McDonalds_on_Interstate_44.jpg

9. Ugly Tabular Data

10. A Simple Restaurant Schema

11. A Simple Restaurant Schema

12. Big Ugly Schema

13. What Went Wrong?
Scripting Languages
facilitate change
....where is the data
model that does the
same?
Things change
Requirements change
User expectations change
Data structures change
Our data models aren’t keeping up

14. Graph Data Models
Deli Liiama
Name
Cuisine
S1 Deli
Price
$

15. Graph Data Models
Peking Inn Deli Liiama
Name
Cuisine
Name S1 Deli
Price
F7
$
Location
Cuisine Location
Chinese Contained-by
San Francisco
S4
Name North Beach

16. Extending Graph Data Models
Deli Liiama
Urban Chic Name
Decor
Cuisine
S1 Deli
Music Price
$
Location
Live DJ
Contained-by
San Francisco
S4
Name North Beach

17. Integrating Graph Data Models
Deli Liiama
Name
Deli Liiama
Name
A2
Cuisine
S1 Deli
Price
OnTap
$
Z6 Brand
Leinenkugel
Brand
Pabst BR

18. Semantic Representation
Relationships are represented explicitly
Schema can be represented as a graph
Data integration is the union of two graphs
This makes creating, extending, and
combining data much easier than before

19. Plugable Data
Data
Semantics allows an
Data
application to utilize
unanticipated new
Data
Data
data sources

20. Plugable Data

21. Data Portability
Data Data
Semantics allows data to
be utilized by
Data
unanticipated new
applications
Data

22. Data Portability
http://dev.mqlx.com/~jamie/simile/timeline.html

23. Data Portability

24. Why Does This Work?
Semantics facilitate shared meaning through
• Subject Identity
• Strong and Consistent Semantics
• Open APIS + Open Data
These principles make it much easier to
extend, combine, and integrate data

25. Just enough RDF

26. Just Enough RDF
RDF is a Data Model
A very simple model!

27. Cosmos was written by Carl Sagan

28. (Cosmos) (was written by) (Carl Sagan)

29. Subject Predicate Object
(Cosmos) (was written by) (Carl Sagan)

30. Subject Predicate Object
(Cosmos) (was written by) (Carl Sagan)
author Carl
Cosmos
Sagan

31. Subject Which Cosmos?
(Cosmos)

32. Subject Which Cosmos?
(Cosmos)

33. Identifiers are Everywhere

34. The humble URI
•URI’s provide strong references
•Much like pointing in the physical
world
“this is red”
“this is a pen”
•a URIref is an unambiguous pointer
to something of meaning

35. Subject Which Cosmos?
(Cosmos)
http://rdf.freebase.com/ns/authority.openlibrary.book.OL3568862M

36. What do you mean, author?
http://rdf.freebase.com/ns/book.written_work.author
author Carl
Cosmos
Sagan
vocabulary

37. There are billions of Carl Sagans...
http://rdf.freebase.com/ns/en.carl_sagan
Cosmos author

38. 0 ”
9 8
d “1
h e
b lis
p u
author Carl
Cosmos
Sagan

39. RDF Data Model
Nodes (“Subjects”)
connect via Links (“Predicates”)
to Objects
• either Nodes or Literals

40. Expressions of RDF
RDF has many (inconvenient) serializations
•RDF-XML
•N3
•Turtle
•NTriples
•RDFa

41. In N-Triples:
<http://rdf.freebase.com/ns/authority.openlibrary.book.OL3568862M>
<http://rdf.freebase.com/ns/book.written_work.author>
<http://rdf.freebase.com/ns/en.carl_sagan> .
author Carl
Cosmos
Sagan

42. In N-Triples:
<http://rdf.freebase.com/ns/authority/openlibrary/book/OL3568862M>
<http://rdf.freebase.com/ns/book.written_work.date_of_first_publication>
“1980” .
Cosmos published “1980”

43. URIs provide identity
http://rdf.freebase.com/ns/en.robert_cook
Stability
Simplicity
Manageability
PURL.org

44. Not all URL’s are good identifiers

45. A socially managed semantic database

46. All objects in Freebase have strong identifiers
http://rdf.freebase.com/ns/en.yorkie

53. Types of things in Freebase

54. 5,203,825 Topics
14,110,006 Named Entites

55. Sources of Freebase Data

56. Freebase is user writable

57. schema = vocabulary

58. Freebase Suggest

59. Freebase Suggest in Drupal

60. Freebase Suggest in Drupal

61. jQuery Freebase Drupal Module
if (module_exists('jquery_freebase')) {
jq_add('freebase');
drupal_add_js(
quot;$(document).ready(function() { $('#edit-taglabel').freebaseSuggest({})
.bind('fb-select', function(e, data) {
$('#edit-taguri').val('http://rdf.freebase.com/ns/' +
new String(data.id).substring(1).replace(///g, '.'));})
});quot;,
'inline'
);
}
http://drupal.org/project/jquery_freebase
Thomas Bonte - Belgium

62. RDF Graphs
Carrie
Starred In Star Wars
Fisher
Starred In
Harrison Blade
Starred In
Ford Runner
Starred In
Daryl
Hannah

63. SPARQL Query
Carrie
Starred In Star Wars
Fisher
Starred In
Harrison Blade
Starred In
Ford Runner
Starred In
Daryl
Hannah
carrie_fisher starred_in star_wars
harrison_ford starred_in star_wars
harrison_ford starred_in blade_runner
daryl_hannah starred_in blade_runner

64. SPARQL Query
carrie_fisher starred_in star_wars
harrison_ford starred_in star_wars
harrison_ford starred_in blade_runner
daryl_hannah starred_in blade_runner
SELECT ? actor WHERE {
fb:harrison_ford fb:starred_in ?movie .
?actor fb:starred_in ?movie .
FILTER (fb:harrison_ford != ?actor)
}

68. Review:
Why is identity important?

69. Data Integration
B B
A A
C C
D
E E
F

70. W3C Vision
Tim Berners-Lee’s
Giant Global Graph

71. The Layer Cake
The Cake
taken from http://www.w3.org/2007/Talks/0130-sb-W3CTechSemWeb/layerCake-4.png

72. Take What You Need
taken from http://www.w3.org/2007/Talks/0130-sb-W3CTechSemWeb/layerCake-4.png

73. Linked Open Data Cloud
(LOD)

75. Drupal is a part of the LOD Cloud
http://drupal.deri.ie/cheese/node/20

76. Drupal is a part of the LOD Cloud
<http://drupal.deri.ie/cheese/node/20> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://drupal.deri.ie/cheese/ns#Cheese> .
<http://drupal.deri.ie/cheese/node/20> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <ov:Cheese> .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#cheese_Title> quot;Ardrahan Cheesequot; .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#created> quot;2009-01-16T11:05:11Zquot;^^http://www.w3.org/2001/
XMLSchema#dateTime .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#changed> quot;2009-04-27T13:20:43Zquot;^^http://www.w3.org/2001/
XMLSchema#dateTime .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#cheese_Source_milk> quot;cowquot; .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#cheese_Country_origin> quot;Irelandquot; .
<http://drupal.deri.ie/cheese/node/20> <ov:origin> quot;Irelandquot; .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#cheese_Picture> <http://drupal.deri.ie/cheese/sites/default/files/
Ardrahan_cheese_1.jpg> .
<http://drupal.deri.ie/cheese/node/20> <http://xmlns.com/foaf/0.1/depiction> <http://drupal.deri.ie/cheese/sites/default/files/
Ardrahan_cheese_1.jpg> .
<http://drupal.deri.ie/cheese/node/20> <http://drupal.deri.ie/cheese/ns#cheese_Description> quot;Ardrahan is a type of semi-soft cheese with
a pungent aroma, Ardrahan cheese has buttery textured honey-coloured centre with a complex delicate flavour. It has a washed rind which
grows into a golden colour, and its size and weight tend to vary slightly due to the fact that it is a hand-made product. In general the large
wheel weighs about 1.5 kg. There is also a small consumer wheel which weighs 300g. It is yellow-coloured.
Ardrahan also develops a nutty flavour with maturity. It has a unique flavour that lingers, leaving a very pleasant after-taste. It contains only
25% fat approximately. It is hand made using traditional methods and only whole milk and vegetarian rennet are used. quot; .
<http://drupal.deri.ie/cheese/node/20> <http://purl.org/dc/elements/1.1/description> quot;Ardrahan is a type of semi-soft cheese with a
pungent aroma, Ardrahan cheese has buttery textured honey-coloured centre with a complex delicate flavour. It has a washed rind which
grows into a golden colour, and its size and weight tend to vary slightly due to the fact that it is a hand-made product. In general the large
wheel weighs about 1.5 kg. There is also a small consumer wheel which weighs 300g. It is yellow-coloured.
Ardrahan also develops a nutty flavour with maturity. It has a unique flavour that lingers, leaving a very pleasant after-taste. It contains only
25% fat approximately. It is hand made using traditional methods and only whole milk and vegetarian rennet are used. quot; .
http://xxx/?q=node/X/rdf

77. RDF in HTML = RDFa
SUBJECT
@about - a URI, stating the RDF subject
PREDICATE
@rel - CURIEs, expressing relationships between two resources
@property - CURIEs, expressing relationships between a resource and a literal
@rev - CURIEs, expressing reverse relationship between two resources
OBJECT
@content - a string, representing a literal RDF object
@href - a URI resource expressing the RDF object (as in-line clickable)
@src - a URI resource expressing the RDF object (as in-line embedded item)
@resource - a URI resource expressing the RDF object
Special Predicate
@typeof - CURIEs expressing the RDF type of a subject (rdf:type)

78. RDF in HTML = RDFa
SUBJECT
@about - a URI, stating the RDF subject
PREDICATE
@rel - CURIEs, expressing relationships between two resources
OBJECT
@resource - a URI resource expressing the RDF object
<div xmlns:fb=”http://rdf.freebase.com/ns/”
about=”http://rdf.freebase.com/ns/en.jamie_taylor”
rel=fb:people.person.place_of_birth>
<span resource=”http://rdf.freebase.com/ns/en.saint_paul”/>
</div>

79. RDF in HTML = RDFa
SUBJECT
@about - a URI, stating the RDF subject
PREDICATE
@property - CURIEs, expressing relationships between a resource and a literal
OBJECT
@content - a string, representing a literal RDF object
<div xmlns:fb=”http://rdf.freebase.com/ns/”
about=”http://rdf.freebase.com/ns/en.carl_sagan”
property=fb:people.person.date_of_birth>
<span content=”1934-11-09”/>
</div>

80. What “concepts” are covered in content
Like existing tagging,
but with strong identifiers!
<resource>
tagged
Tag taggingDate quot;2001-01-01quot;
label means
quot;textquot; <resource>
Strong identifier goes here!

81. Drupal Module

82. <resource>
tagged
Tag taggingDate
label means
<div class=quot;rdfaquot; quot;textquot; <resource>
xmlns:ctag=quot;http://commontag.org/ns#quot;>
NASA's
<a typeof=quot;ctag:Tagquot;
rel=quot;ctag:meansquot;
href=quot;http://rdf.freebase.com/ns/en.phoenix_mars_missionquot;
property=quot;ctag:labelquot;>Phoenix Mars Lander</a>
has deployed its robotic arm.
</div>