Semantic+Web

= Semantic Web = toc

The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF).(1) While it is still somewhat of a theoretical framework, there has been successful use of it in some fields, and many individuals and institutions have begun to create data in preparation for a near-future when the web adopts a wholly semantic nature. In the web of today, documents, not data, are shared, and data is locked into isolated applications, which greatly reduces the usability and re-usability of that data. The vision of the Semantic Web is to extend principles of the Web from documents to data. Data should be accessed using the general Web architecture and should be related to one another just as documents (or portions of documents) are already. This also means creation of a common framework that allows data to be shared and reused across application, enterprise, and community boundaries, to be processed automatically by tools as well as manually, including revealing possible new relationships among pieces of data.(1)

Uses
Semantic Web technologies can be used in a variety of application areas. They include, but are not limited to:


 * in data integration, whereby data in various locations and various formats can be integrated in one, seamless application
 * in resource discovery and classification to provide better, domain specific search engine capabilities
 * in cataloging for describing the content and content relationships available at a particular Web site, page, or digital library
 * by intelligent software agents to facilitate knowledge sharing and exchange
 * in content rating
 * in describing collections of pages that represent a single logical "document"
 * for describing intellectual property rights of Web pages

Examples
Because the semantic web will change more of how we conceptualize and utilize the web, not how we physically view the web, it can be difficult to describe. We will not necessarily "see" the semantic web in a new user interface, for example, we will just experience the benefits of its implementation. This excerpt, taken from Tim Berner’s-Lee’s 2001 article in Scientific American (1), describes a future in which the semantic web has evolved:

//The entertainment system was belting out the Beatles' "We Can Work It Out" when the phone rang. When Pete answered, his phone turned the sound down by sending a message to all the other local devices that had a volume control. His sister, Lucy, was on the line from the doctor's office: "Mom needs to see a specialist and then has to have a series of physical therapy sessions. Biweekly or something. I'm going to have my agent set up the appointments." Pete immediately agreed to share the chauffeuring.//

//At the doctor's office, Lucy instructed her Semantic Web agent through her handheld Web browser. The agent promptly retrieved information about Mom's prescribed treatment from the doctor's agent, looked up several lists of providers, and checked for the ones in-plan for Mom's insurance within a 20-mile radius of her home and with a rating of excellent or very good on trusted rating services. It then began trying to find a match between available appointment times (supplied by the agents of individual providers through their Web sites) and Pete's and Lucy's busy schedules. (The emphasized keywords indicate terms whose semantics, or meaning, were defined for the agent through the Semantic Web.)//

//In a few minutes the agent presented them with a plan. Pete didn't like it - University Hospital was all the way across town from Mom's place, and he'd be driving back in the middle of rush hour. He set his own agent to redo the search with stricter preferences about location and time. Lucy's agent, having complete trust in Pete's agent in the context of the present task, automatically assisted by supplying access certificates and shortcuts to the data it had already sorted through.//

//Almost instantly the new plan was presented: a much closer clinic and earlier times - but there were two warning notes. First, Pete would have to reschedule a couple of his less important appointments. He checked what they were - not a problem. The other was something about the insurance company's list failing to include this provider under physical therapists: "Service type and insurance plan status securely verified by other means," the agent reassured him. "(Details?)"//

//Lucy registered her assent at about the same moment Pete was muttering, "Spare me the details," and it was all set. (Of course, Pete couldn't resist the details and later that night had his agent explain how it had found that provider even though it wasn't on the proper list.)//

//The Semantic Web will bring structure to the meaningful content of Web pages, creating an environment where software agents roaming from page to page can readily carry out sophisticated tasks for users. Such an agent coming to the clinic's Web page will know not just that the page has keywords such as "treatment, medicine, physical, therapy" (as might be encoded today) but also that Dr. Hartman works at this clinic on Mondays, Wednesdays and Fridays and that the script takes a date range in yyyy-mm-dd format and returns appointment times. And it will "know" all this without needing artificial intelligence on the scale of 2001's Hal or Star Wars's C-3PO. Instead these semantics were encoded into the Web page when the clinic's office manager (who never took Comp Sci 101) massaged it into shape using off-the-shelf software for writing Semantic Web pages along with resources listed on the Physical Therapy Association's site.//

The semantic web has not yet evolved to the point that the above scenario is feasible, though it is a rational endeavor to work towards. For more concrete examples, there are websites that utilize concepts of the semantic web today:


 * Sun’s white paper collection site: []
 * Harper’s online magazine: []
 * Yahoo!’s finance portal: []

For a more comprehensive list of case studies and use cases: []

** Essential Elements **
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 * Introduction to the Semantic Web **


 * Tim Berners-Lee on the Semantic Web**

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** Books on the Semantic Web **
[]

** References **
1. Berners-Lee, Tim, Hendler, James, & Lassila, Ora. (17 May 2001). "The Semantic Web." //Scientific American.// []

2. W3C: Semantic Web Activity. 2011. []