Link awareness

Link awareness is defined as the ability to discover, view, search and update global hyperlink information about any resource with a URL on the World Wide Web. This global link information is a shared information resource.

Implementing link awareness is difficult. In practice, an implementation only approximates link awareness. There are at least two qualitative axes on which we can classify these implementations.

• Breadth of coverage: The number and type of interlinked documents covered.
• Liveness: The ability (or lack thereof) to update the link information on the fly.

Implementation examples

• Most WikiWiki implementations support link awareness within the scope of the documents that they host. Their breadth of coverage (insofar as link information is concerned) is narrow. A wiki, however, is very live (and indeed, liveness, is its raison d'etre).
• Google supports link awareness through its web interface. (You type in a query of the form link:<URL>.) Google's breadth is impressive (it covers a lot of interlinked documents), but it is a far cry from live (it can take months before Google indexes a newly created document).

Related reading

• Gibson; Kleinberg; Raghavan. "Structural Analysis of the World Wide Web". http://www.w3.org/1998/11/05/WC-workshop/Papers/kleinber1.html. 
• Chakrabarti; Gibson; McCurley. "Surfing the Web Backwards". http://www8.org/w8-papers/5b-hypertext-media/surfing/surfing.html.