Today’s podcast is on the topic of RDFa. RDFa or (Resource Description Framework – in – attributes) is a set of extensions to XHTML which is now a W3C Recommendation.
RDFa uses attributes from XHTML’s meta and link elements, and generalizes them so that they are usable on all elements. This allows you to annotate XHTML markup with semantics.
To better understand the benefits, functionality and how to implement RDFa I met up with Manu Sporny, CEO of Digital Bazaar, Inc. a provider of technology and services to enable individuals and businesses to buy and sell digital content via the Internet.
According to Wikipedia, The W3C RDF in XHTML Taskforce is also working on an implementation for non-XML versions of HTML. The primary issue for the non-XML implementation is how to handle the lack of XML namespaces.
In April 2007 the XHTML 2 Working Group produced a module to support RDF annotation within the XHTML 1 family.[6] As an example, it included an extended version of XHTML 1.1 dubbed XHTML+RDFa 1.0. Although described as not representing an intended direction in terms of a formal markup language from the W3C, limited use of the XHTML+RDFa 1.0 DTD did subsequently appear on the public Web.
Benefits of RDFa include:
Five “principles of interoperable metadata” met by RDFa.
* Publisher Independence – each site can use its own standards
* Data Reuse – data is not duplicated. You do not need separate XML and HTML sections 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.
Check out today’s three minute podcast on the Web Professional Minute website.
Today’s minute is sponsored by the Web Master Survival Guide. When you need professional resources, be sure to check out webmastersurvivalguide.com There is something there for all skill levels and disciplines and be sure to ask about advertising opportunities with this PR6 website from the World Organization of Webmasters.
Transcript:
Bill Cullifer: I am here with Bill Cullifer, founder and CEO of digital bazar on the topic of RDFA. Manu good afternoon and thanks for agreeing to this interview.
Manu Sporny: Well thanks for having me.
Bill Cullifer: Manu what is RDFA first of all and can you summarize the session that you had here today and how can web professionals benefit?
Manu Sporny: Sure, well RDFA is really a part of a bigger movement on the web right now, which is this concept of web semantics right so, web semantics is basically the idea that we want to make the web understandable by computers as well as humans all right, so we want to embed the semantic information on the web and by semantic information I mean, things like people and places and events and we want to make sure that computers can identify those things online so, if computers can understand you know what constitutes a web page, what exactly is in this web page such as people, places, events, it can start helping the search engine companies give you web pages that mean much more to you than they do right now all right, so when you search for a person it can actually extract the people on a web page and say hey!
These are the people that I know for a fact exist on the web page you know RDFA is a mechanism to mark up this information on the web page so, it is kind of similar to the micro formats community and the micro formats movement. RDFA is built to be a bit more scalable than micro format, so where both going, you know both of these communities are going towards the same goal which is how do you make a machine understand a web page.
Bill Cullifer: Fair enough, well said and so what would be the specific steps you know for the subscribers in this pod cast, how do they get involved in what exactly do they have to do?
Manu Sporny: Okay, well the first thing is you know you have to kind of learn RDFA, which isn’t that isn’t as hard as you would think it is, it is just a couple of attributes on XHTML, so if you know how to edit an HTML document it can already write RDFA. The best resource to go to right now is the rdfa.info website, so if you go to the Wiki specifically rdfa.info/wiki that has a whole bunch of links on how you can kind of start and its got some basic overview and then it has well if you want to mark up people or places or events or music or movies its got instructions on how you do that as well on that website.
Bill Cullifer: Excellent, thank you so much.
Manu Sporny: No problem.