What is the Semantic Web, Actually?

I've read several blog posts reacting to John Markoff's article today. There seem to be some misconceptions in those posts about what the Semantic Web is and is not. Here I will try to  succinctly correct a few of the larger misconceptions I've run into:

• The Semantic Web is not just a single Web. There won't be one Semantic Web, there will be thousands or even millions of them, each in their own area. They will all be part of one Semantic Web in that they will use the same open-standard languages and their data will be universally accessible, but they won't all be run by any single company. They will connect together over time, forming a tapestry. But nobody will own this or run this as a single service. It will be just as decentralized as the Web already is.
• The Semantic Web is not separate from the existing Web. The Semantic Web won't be a new Web apart from the Web we already have. It simply adds new metadata and data to the existing Web. It merges right into the existing HTML Web just like XML does, except this new metadata is in RDF (since RDF can in fact be expressed in XML).
  
• The Semantic Web is not just about unstructured data. In fact, the Semantic Web is really about structured data: it provides a means (RDF) to turn any content or data into structured data that other software can make use of. This is really what RDF enables.
• The Semantic Web does not require complex ontologies. Even without making use of OWL and more sophisticated ontologies, powerful data-sharing and data-integration can be enabled on the existing Web using even just RDF alone.
• The Semantic Web does not only exist on Web pages. RDF works inside of applications and databases, not just on Web pages. Calling it a "Web" is a misnomer of sorts -- it's not just about the Web, it's about all information, data and applications.
• The Semantic Web is not only about AI, and doesn't require it. There are huge benefits from the Semantic Web without ever using a single line of artificial intelligence code. While the next-generation of AI will certainly be enabled by richer semantics, AI is not the only benefit of RDF. Making data available in RDF makes it more accessible, integratable, and reusable -- regardless of any AI. The long-term future of the Semantic Web is AI for sure -- but to get immediate benefits from RDF no AI is necessary.
• The Semantic Web is not only about mining, search engines and spidering. Application developers and content providers, and end-users, can benefit from using the Semantic Web (RDF) within their own services, regardless of whether they expose that RDF metadata to outside parties. RDF is useful without doing any data-mining -- it can be baked right into content within authoring tools and created transparently when information is published. RDF makes content more manageable and frees developers and content providers from having to look at relational data models. It also gives end-users better ways to collect and manage content they find.
• The Semantic Web is not just research. It's already in use and starting to reach the market. The government uses it of course. But also so do companies like Adobe, and more recently Yahoo (Yahoo Food has started to use some Semantic Web technologies now). And one flavor of RSS is defined with RDF. Oracle has released native RDF support in their products. The list goes on...

Learning more:

• To learn about the technology of RDF, I recommend this terrific presentation by my friend Ian Davis.
• This is my long-term outlook for the Web and the Semantic Web.
• PlanetRDF is a good feed to read if you want to keep up with what's going on in this field.
• My own company, Radar Networks, is working on bringing the Semantic Web to the masses. You can sign up for our launch list at our site to be notified of future announcements.

Comments

[Yihong Ding]

Very nice summary. Currently, I and some other researchers are working on a new paper about realizing the Semantic Web. Quite a few of these thoughts match exactly what we believe in our paper. Maybe we can have a share of ideas after our paper is finalized.