— DRAFT —

Talking Points for Semantic Web vs. Web2.0

Background

One of the main aspects of Web2.0, ie, that applications are based on combining various type of data that are spread all around on the Web, coincides with the very essence of the Semantic Web. What the SW provides is a consistent model and tools for the definition and the usage of qualified relationships among data on the Web. There are differences, of course: Semantic Web is like Web 2.0 (in this respect) but with more general, standardized, and possibly more expressive data models. In some cases problem may get really hard and needs inferences, reasoning services; but Web 2.0 will be able to seamlessly “upshift” to RDF Schemas, SKOS, OWL, or Rules, making use of the greater expressibility of those technologies. Which will continue the historical trend of putting more smarts into the data so that code becomes simpler and programmer’s time becomes more productive.

The big picture: imagine having one query language, one client, and one data access protocol which let you arbitrarily slice the data of Flickr, delicious, Google, and your favorite Web 2.0 sites, FOAF files, RSS 1.0 feeds — plus anything that can be mapped into RDF. This is data integration the Web 2.0 and the Semantic Web way.

Similarities

Both Worlds

• focus on the data
• focus on intelligent data sharing, integration, combination (something that the Semantic Web has been pushing for years)
• focus on using appropriate and specific data formats for specific jobs; (e.g., RDF over bare XML for the SW, JSON or similar over XML/XHTML for Web 2.0)
• focus on defining and using simple data formats
• focus on community based developments of common terminologies
• treat Web clients as first-class data consumers & producers

Differences

• the SW, when it becomes necessary, may use more complex formalisms (like RDF Schemas, OWL, or Rules) and their related algorithms to solve harder problems
• the SW puts a great emphasis on describing and defining the relationships among data, which gets less focus in Web 2.0
• the SW is less focused on the human user experience, in contrast to Web 2.0 that is also focused on user interface aspects

Some technologies on congruence

• RDF: gives a uniform data model for data combination and interchange
• SPARQL: gives the SW and Web 2.0 a common data access language against the RDF data model, with result formats in XML or JSON
• RDFa: that embeds SW data into documents, offering a more rigorous and general alternative to microformats
• GRDDL: that provides a bridge between microformat type annotation of content and/or RDFa on the one hand, and a general RDF formalism on the other (thereby making it possible to combine, e.g., microformats with SPARQL queries)
• AJAX components: provide the flexibility to combine dynamic Web 2.0 pages with the data combination tools like SPARQL interfaces