1. Why RDFa?

2. Why RDFa
Session 3/4

3. A better web...
http://www.sti2.org/service-web-3-0-the-future-internet-mov-medium

4. RDF (and RDFa) fundamental, enabling, ubiquitous, non proprietary...
RDFa

5. RDF (and RDFa) fundamental, enabling, ubiquitous, non proprietary...
internet of things!
The Semantic Web
semantic web
semanticised web
web of data
linked data
web 3
RDF
RDFa

6. Why RDFa?
Benefits of RDFa
Five "principles of interoperable metadata" met by RDFa.
‣ publisher independence—each site can use its own standards
‣ data reuse—data is not duplicated, separate XML and HTML sections are not
required for the same content
‣ self containment—the HTML and the RDF are separated
‣ schema modularity—the attributes are reusable
‣ evolvability—additional fields can be added and XML transforms can extract
the semantics of the data from an XHTML file
Additionally RDFa may benefit web accessibility as more information is available to
assistive technology.
http://ben.adida.net/presentations/w3c-2006-04-06/w3c-2006-04-06.pdf

7. Metadata—improved information discovery and retrieval
RDFa and SEO
webBackplane, Mark Birbeck on December 16 2009
Vertical search engines
RDFa will allow the search giants to offer partitioned search engines, aimed at
particular audiences.
There are many search engines already available, for specialist areas, but most of
them tend to be out of date, or missing information altogether.
The major search engines are often crawling these sites already, but page ranking
algorithms will hide them away in the 1000th page of search results. By adding
targeted mark-up to web-pages it becomes easier for search engines to differentiate
the subject-matter of the pages, and so offer specialised views on their data.
http://webbackplane.com/mark-birbeck/blog/2009/12/rdfa-and-seo

8. Metadata—improved information discovery and retrieval
RDFa and SEO
webBackplane, Mark Birbeck on December 16 2009
Improved search accuracy
This is beneficial for the users of search engines, in that it can help them to find the
information they want, faster. But it's also significant for site creators and SEO
practitioners, because it means that sites are increasingly found in the right place.
An increasing part of SEO is writing relevant articles that relate to products and
services. Since search engines are increasingly clever enough to differentiate
between a bunch of keywords dumped into a page, and an article with real content,
a virtuous circle is created, rewarding 'proper' articles with improved rankings.
RDFa can help—it allows authors to make pages unambiguous.
http://webbackplane.com/mark-birbeck/blog/2009/12/rdfa-and-seo

9. Metadata—improved information discovery and retrieval
RDFa and SEO
webBackplane, Mark Birbeck on December 16 2009
Improving display of results
This is the area that has probably seen most discussion recently, in the context of
Yahoo!'s enhanced results, and Google's rich snippets… Benefits to the search
engine of doing this, are that users can get more done, on their site, making them
more likely to return. The benefits for the companies are improved click-through.
For many, click-through is more important than ranking. Some SEO experts say that
if adding RDFa to a site gave an increase in click-through of only a couple of %,
sites would see that as worth it—yet as Peter Mika said in Year of the Monkey:
Lessons from the first year of SearchMonkey, adding RDFa or Microformats to a
page gives significantly better click-through than a mere few %.
http://webbackplane.com/mark-birbeck/blog/2009/12/rdfa-and-seo

10. Improving data distribution
How RDFa can help democratise web data
Mark Birbeck, Google Tech Talk, June 2009
I’m using RDFa as a bit of a shorthand, because I’m saying really “embedded
metadata”. I’m saying any way of actually putting information into the HTML page,
rather than the traditional semantic web approach of having a “separate channel”.
By separate channel, I’m saying you might have had an RDF-XML document, or
even an RSS feed you could regard as a kind of semantic channel of information.
But a channel of information that’s kind of distinct from the web page.
Whereas what we’ve done with RDFa, and what the people behind Microformats
were doing, basically the same goal, was actually make the HTML page the carrier
of the metadata. And some times it’s carrying metadata about other things, and
sometimes it’s carrying metadata about itself. So really, when I say RDFa
(throughout this talk) I’m generally meaning those kind of solutions that allow you
to embed metadata.
The reason I’m favouring RDFa is because it’s very specific goal was to align itself
with RDF, so it’s actually much more precise than Microformats, but the idea is the
same that you embed information [in the HTML page].
http://www.youtube.com/watch?v=-fko_UCGCIs&feature=player_embedded#

11. Improving data distribution
How RDFa can help democratise web data
Mark Birbeck, Google Tech Talk, June 2009
As for what it is, it’s a W3C standard now. It’s something we’ve been working on for
four or so years—which I guess is quick for the W3C, we’ve been working on it for
quite a long time, and it recently became a standard.
And it’s very much about defining the syntax of how you embed information. It’s
not really about saying what the vocabularies should be. Whereas Microformats is
very much more about the vocabularies.
And a good example of the flexibility of what that brings is when Google did its Rich
Snippets, it just came out with its own vocabulary. It got a lot of stick for it from
the Semantic Web community, or some there. But the point is that you were able to
just come out with your own vocabulary, because RDFa is about the syntax and the
structure, rather than the actual terms.
So it’s very much in the spirit of the Web in the sense that it allows people to define
their own vocabularies or reuse existing vocabularies, and put them into their
documents however they see fit.
So RDFa is a standard, and its goal is embedding metadata in pages.
http://www.youtube.com/watch?v=-fko_UCGCIs&feature=player_embedded# (11:27–22:43)

12. The “open data” movement
Linking Open Data project
The goal is to extend the web by publishing various open data sets as RDF on the
web and by setting RDF links between data items in different data sources. These
RDF links then enable navigation from a data item within one data source to related
data items within other sources using a semantic web browser.
RDF links can also be followed by the crawlers of semantic web search engines,
which may provide sophisticated search and query capabilities over crawled data.
As query results are structured data and not just links to HTML pages, they can be
used within other applications.
http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData/

13. The “open data” movement
http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData/

14. The “open data” movement
Contains 4.7 billion triples, interlinked by
around 142 million RDF links
http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData/

15. The “open data” movement
A web of data
‣ web of data is generic (can contain any type of data)
‣ anyone can publish to web of data
‣ no constraints due to vocabularies (can create own as required)
‣ “things” connected via RDF links provide a global data graph which can be
used for new resource discovery
‣ separation of data and presentation
‣ data is self describing (doesn't require additional information)
‣ HTTP and RDF are essentially the common API rather than many other
proprietary heterogeneous models and interfaces
‣ open model, new stuff added easily
RDFa

16. Discovery using RDF links
DBpedia applications
DBpedia is RDF data extracted from the well structured wikipedia
pages (13 million)
‣ open web page at: http://wiki.dbpedia.org/Applications
‣ select the “Relation Finder” application
‣ on the left hand side of the page enter two “entities” that are likely to have
several mentions in wikipedia
‣ select “Find Relations” and watch the RDF links begin to match up to reveal
interesting direct and indirect information about the entities
‣ explore some of the other DBpedia applications and determine if there is any
relevance to your own work