WTF is Semantic Web?

Miles Worthington

Lots of new terms

• Linked Data

• triples

• RDF

• SPARQL

• ontology

It’s this guy’s idea

• Director of W3C

• Father of the Internet

• Fortune teller

Tim Berners-Lee

One possibility...

==

More likely

He drives one of these

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

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

?

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

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

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

and sometimes...

is amazing!

is amazing!

...at guessing

There is a common problem we all experience

on the Web.

Jim’s watching a football match...

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

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

Why did I bother...?

It’s not even real football!

FAIL

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

Normal Web is about making information accessible to people.

Semantic Web is about making information more accessible

to software.

Thank you Wikipedians

(Thank you, Wikipedians)

Thank you Wikipedians

(Thank you, Wikipedians)

oh well, it'll

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

• Give important things identifiers

How?

• Give important things identifiers

How?

• Give important things identifiers

How?

407161495 ?

• Give important things identifiers

How?

407161495 ?

footballer_f285n ?

• Give important things identifiers

How?

407161495 ?

footballer_f285n ?

michael_jackson_27 ?

Just use the URI scheme I came up with years ago!!!

How?

Just use the URI scheme I came up with years ago!!!

How?

Uniform Resource Identifier

“URI”

• Give important things identifiers

How?

407161495 ?

footballer_f285n ?

michael_jackson_27 ?

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

URIs and URLs

• They look exactly like URLs

• In fact, URLs are a type of URI

URI: An identifier

URL: An identifier that points to a document

• They look exactly like URLs

• In fact, URLs are a type of URI

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

URL

URI

URIs and URLs

• They look exactly like URLs

• In fact, URLs are a type of URI

http://milesworthington.com/Michael_Jackson(page does not exist)

URL

URI

URIs and URLs

URIs and URLs

• They look exactly like URLs

• In fact, URLs are a type of URI

Often the same.

But URIs do not always point to actual pages. Sometimes they are just names.

• Give important things identifiers

How?

• Give important things identifiers

• Also give identifiers to the relationships between things

How?

FAIL

Jim

FAIL

FAIL

http://jimsblog.com/michael_jackson_match.html

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

Traditional Web links

http://jimsblog.com/michael_jackson_match.html

foaf:primaryTopic

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

Semantic Web links

http://jimsblog.com/michael_jackson_match.html

foaf:primaryTopic

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

(URI in disguise)

http://jimsblog.com/michael_jackson_match.html

http://xmlns.com/foaf/0.1/primaryTopic

http://en.wikipedia.org/wiki/Michael_Jackson_(footballer)

Jim’s blog post

has a the primary topic of

Michael Jackson the football player

Jim’s blog post

has a the primary topic of

Michael Jackson the football player

This is referred to as a “triple”

FAIL

FAIL

FAILMOAR METADATA!!

FAILMOAR METADATA!!

This is RDFa, a practical way

to semanticize the Web

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

Remember when we used <font> tags to

style Web pages?

Then some smart people suggested we separate

structure and presentation...

...and now we have HTML + CSS

Now we have smart people suggesting we separate

raw, meaningful content and presentational content

Content formatted for softwarevs.

Content formatted for humans

We need to treat software the same way we treat humans.

Software has feelings too!

Linked Data

Tim is right.

I want to be available to everyone.

I support Linked Data!

Linked Data

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

MJ’s DBpedia URI

http://dbpedia.org/resource/Michael_Jackson

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

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

Michael Jackson

was born in

Gary, Indiana

“Triples”

“Triples”

http://dbpedia.org/resource/Michael_Jackson

http://dbpedia.org/ontology/birthPlace

http://dbpedia.org/resource/Gary%2C_Indiana

“Triples”

SUBJECT

PREDICATE

OBJECT

“Triples”

http://dbpedia.org/resource/Michael_Jackson

http://dbpedia.org/ontology/birthDate

“1958-08-29”

Anyone can decide URIs.

You can make your own and still link to others.

http://www.imdb.com/name/nm0001391/

http://www.w3.org/2002/07/owl#sameAs

http://dbpedia.org/resource/Michael_Jackson

RDF

RDF

• “Resource Description Framework”

• Provides a way to add identifiers (URIs)to content

• Comes in many flavors

RDF

@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/> ] .

Turtle format

RDF

<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".

N-triples format

RDF

<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>

RDF/XML

“Do they really expect us to create two versions of our

content?”

“One HTML and one RDF?”

The Compromise: RDFa

• RDF that lives inside an HTML document

• The “a” stands for attributes

• Uses attributes on HTML tags to hold identifiers

The Compromise: 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>

RDFa

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

Drupal 7 publishes basic RDFa out of the box

Wordpress has plugins to publish RDFa

“But why is any of this important?”

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

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>”

Geek Reason

More possibilities for semantic search...

Geek Reason

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

Geek Reason

It will enable developers to build tools we can can hardly

conceive of right now.

The Real Reason

SEO

The Real Reason

SEOBut not just the $$$ part!

The Real Reason

SEOWith so much content on the Web,

there’s a real need to improve our findability

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

Thanks!