Introduction to RDF & Microformats
Tim Wright
What you're in for
After a long a day of work we get to talk about MORE work.
RDF > A Little History
- Version 1: WC3 Specification in 1999
- Version 2: WC3 Specification in 2004
- Evolutionary stage for the Web
- Integrating with automated software using machine readable information
- Increased efficiency
- Moving the Web forward
RDF and "The Semantic Web"
W3C's "Semantic Web Vision" is a future where:
- Web information has exact meaning
- Web information can be understood and processed by computers
- Computers can integrate information from the web
w3schools
RDF > What is it?
- Resource Description Framework
- Framework for structuring data
- Making statements about resources
- Creates machine–readable content
- Allows for sharing data
- How?
- Let's hope I know...
RDF > Data Sharing
- Creating universal standards for data structure
- Open sharing
[Medical data example]
RDF > Formats
RDF is most commonly written in 2 formats
- XML
- N3 (Notation 3) – designed to be easier to write by hand
- Both stick to the triples format (subject - predicate - object)
RDF > XML Anatomy
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<rdf:Description rdf:about="http://en.wikipedia.org/wiki/Tony_Benn">
<dc:title>Tony Benn</dc:title>
<dc:publisher>Wikipedia</dc:publisher>
</rdf:Description>
</rdf:RDF>
The title [property] of this resource, which is published by wikipedia [resource] is “Tony Benn [value]”
RDF > A quick look at N3
<http://en.wikipedia.org/wiki/Tony_Benn>
<http://purl.org/dc/elements/1.1/title>
"Tony Benn" .
<http://en.wikipedia.org/wiki/Tony_Benn>
<http://purl.org/dc/elements/1.1/publisher>
"Wikipedia" .
(should be on 1 line)
RDF > Popular applications
- RSS
- RDF Site Summary
- Rich Site Summary
- Really Simple Syndication
- RDFa & XHTML
- Microformats (not actually RDF - uses pre-existing XHTML attributes)
RSS
RSS 1.0 > Header
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://purl.org/rss/1.0/">
<channel rdf:about="http://www.xml.com/xml/news.rss">
<title>XML.com</title>
<link>http://xml.com/pub</link>
<description>
XML.com features a rich mix of information and services
for the XML community.
</description>
...
RSS
RSS 1.0 > Item
<item rdf:about="http://xml.com/pub/2000/08/09/xslt/xslt.html">
<title>Processing Inclusions with XSLT</title>
<link>http://xml.com/pub/2000/08/09/xslt/xslt.html</link>
<description>blah blah blah</description>
</item>
Kind of a pain to write...
RSS
RSS 2.0 > Header
<?xml version="1.0"?>
<rss version="2.0">
<channel>
<title>Lift Off News</title>
<link>http://liftoff.msfc.nasa.gov/</link>
<description>Liftoff to Space Exploration.</description>
<language>en-us</language>
...
RSS
RSS 2.0 > Item
<item>
<title>Title of post</title>
<link>http://www.csskarma.com/blog/p=13</link>
<description>This is a little about the article</description>
<pubDate>Thurs, 15 Jan 2009</pubDate>
</item>
RDF > RDFa & XHTML
- What is it?
- Set of XHTML attributes adding in machine–readable hints
- Knowledge gap between humans and programs
RDF > RDFa & XHTML
How does it apply to you?
Marking up contact information
From:
<div>
<p>Alice Birpemswick</p>
<p>Email: <a href="mailto:alice@example.com">alice@example.com</a></p>
<p>Phone: <a href="tel:+1-617-555-7332">+1 617.555.7332</a></p>
</div>
Marking up contact information
To:
<div typeof="foaf:Person" xmlns:foaf="http://xmlns.com/foaf/0.1/">
<p property="foaf:name">Alice Birpemswick</p>
<p>Email: <a rel="foaf:mbox" href="mailto:alice@example.com">alice@example.com</a></p>
<p>Phone: <a rel="foaf:phone" href="tel:+1-617-555-7332">+1 617.555.7332</a></p>
</div>
FOAF stands for "friend of a friend". It's use to describe people and their relationships.
The Problem & Solution
- STILL kind of a pain to implement
- Enter: Microformats
Microformats > Basic Types
- rel attribute
- vote links (rev)
- xfn
Microformats > The "rel" attribute
This link's relationship to the current document [This is an external site]
<a href="/tags/css/" rel="tag">CSS</a>
or
<a href="http://www.yahoo.com" rel="external">CSS</a>
Benefits: Search engines already using nofollow, license and tag
Microformats > vote links & "rev"
Current document's relationship to the link [I support this link]
Let's say you love Yahoo!
<a href="http://www.yahoo.com"
rev="vote-for">Yahoo!</a>
Microformats > vote links & "rev"
Or you harbor resentment towards Google
<a href="http://www.google.com"
rev="vote-against">Google</a>
Microformats > vote links & "rev"
And you have no strong feelings about CNN
<a href="http://www.cnn.com"
rev="vote-abstain">CNN</a>
Microformats > Ideal rev
Why would you ever use this stuff?
To create more relevant search results
Microformats > XFN
Marking up a link to another site of yours
<a href="http://www.twitter.com/csskarma"
rel="me">Twitter/CSSKarma</a>
If my mom had a web site
<a href="http://www.timsmom.com"
rel="parent met">Tim's mom</a>
Microformats > Advanced Types
- hCard – Contact information
- hCal – Events
- hReview – Movie/Book/Product reviews
Microformats > hCard
<div id="hcard-Tim-C-Wright" class="vcard">
<a class="url n" href="http://www.usc.edu/web/">
<span class="given-name">Tim</span>
<span class="family-name">Wright</span>
</a>
<div class="adr">
<div class="street-address">3434 S. Grand Ave</div>
<span class="locality">Los Angeles</span>,
<span class="region">CA</span>,
<span class="postal-code">90007</span>
</div><!--/adr-->
</div><!--/vcard-->
hCard generator: microformats.org/code-tools
Microformats > hCal
<div id="hcalendar-LA-Semantic-Web-Meetup" class="vevent">
<a href="http://semweb.meetup.com/32/calendar/9380423/" class="url">
<abbr title="2009-01-15T07:00-08:0000" class="dtstart">
January 15, 2009 7:00pm</abbr>
–
<abbr title="2009-01-15T09:00-08:00" class="dtend">9pm</abbr> :
<span class="summary">LA Semantic Web Meetup</span> at
<span class="location">Yahoo! Training Room</span></a>
<div class="description">
The January Semantic Web group
will Meetup will be from 7pm to 9pm
</div><!--/description-->
</div><!--/vevent-->
hCal generator: microformats.org/code-tools
Microformats > hReview
<div id="hreview-Very-good-book" class="hreview">
<h2 class="summary">Very good book</h2>
<abbr title="2004-01-11T19:15-08:00" class="dtreviewed">
Jan 11, 2004</abbr>
by <span class="reviewer vcard">
<span class="fn">Tim Wright</span>
</span>
<span style="display: none;" class="type">product</span>
<div class="item"><a href="http://www.bulletproofajax.com" class="fn url">Bulletproof Ajax</a>
</div>
<abbr class="rating" title="5">★★★★★</abbr>
hReview generator: microformats.org/code-tools
Microformats > vEntry
<div class="v120vEntry">
<div class="vstill">
<a href="/user/spoiledmilk"><img src="2.jpg" class="vimg"></a>
</div><!--/vstill-->
<div class="vtitle">
<a href="/profile?user=spoiledmilk">spoiledmilk</a>
</div><!--/vtitle-->
<div class="vfacets">
<span class="grayText">Joined:</span> August 02, 2006<br>
<span class="grayText">Videos:</span> <a href="/profile_videos?user=spoiledmilk">21</a>
</div><!--/vfacets-->
</div><!--/v120vEntry-->
Microformats > Why?
- Benefits
- Low cost of implementation
- Someone has to do it
- High cost for software to initiate
- Pitfalls
- Bringing the internet past the limitations of the Web browser
Microformats > In the news
Recently BBC annouced they would drop the hCal format from their site.
Plugs > S5
- It's a Simple Standards-based Slide Show System
- One XHTML document provides all of the slide show's content
- CSS handles the layout and look of the slides
- JavaScript handles the dynamic aspects of the show
- Downloadable at: meyerweb.com/eric/tools/s5/
ReplyTo: Everyone in this room
- Semantic Ninjas
- Make the Web more than just the Internet
Thanks for listening
That's all.
Contact Info
