Semantic Web

I’ve been trying to get my arms around the semantic web movement, and finally decided to devote some time to the topic this morning.  First, let’s break down this phrase by defining the two words (courtesy of Websters.com):

semantic - “of, pertaining to, or arising from the different meanings of words or other symbols…“

web - “something formed by or as if by weaving or interweaving.”

So we have a weaving together of the different meanings of words or symbols, and presumably other objects such as video clips and files.  So how is that different from the version of the “web” we’ve weaved today?  The answer comes from an old Twilight Zone episode - it’s another dimension.  The semantic web concept boils down to providing context (or dimensions) to the words, phrases, files, and other detritus that’s floating around out there now.  The “Web 2.0” movement is attempting to address this issue, by building a community that comments on subject areas, thereby giving others context on that subject area.  The semantic web concept goes beyond this, by embedding this extra dimension into the structure in which content is stored.  Which highlights another important difference: Who gets to define content?  The author, or the viewers?  Ideally it would be both, with the ability to determine gaps in the definitions.  So where “Web 2.0″ supports the viewer definition, the “Semantic Web” as advertised today encompasses technologies that support the author definition.   But going back to our original breakdown of this phrase, in particular the piece about “weaving together of the different meanings of words and symbols” - doesn’t that mean capturing both author and viewer definitions? 

Leaving all the philosophical discussions aside, how do you implement a “semantic web” solution? And what are the benefits and drawbacks? The implementation starts with how the data is stored.  A 1.0/2.0 generation website stores information in HTML files that are then directly translated and presented via a browser.  A semantic website stores information in a structured format (either a database, Resource Description Framework or XML file) that supports a metadata layer.  The metadata layer provides this extra dimension, by allowing descriptors to be stored on the content itself.  This also decouples the storage from the presentation, which provides flexibility at a cost of presentation speed.  This allows the content to be translated for web page viewing, but more importantly allows other applications to accurately integrate the data, by using the metadata as a roadmap.  Thereby creating a web within a web, where applications (calendering system) talk to one another without human intervention.  The benefit - all the data on this new web becomes much more valuable because of the leverage you get by combining content across multiple sites.  The downside is the enormous cost and effort to implement a semantic web solution.  There is an order of magnitude difference between putting content in an HTML file and storing data in a structured format with associated metadata.

What does the future hold for the semantic web? Data that has significant value to the author or publisher will migrate towards a structured solution.  These semantic enabled sites will then link up on an opportunistic basis, forming informal networks based on common interests.  As these networks grow, the value proposition (and technological capabilities) will allow more sites to migrate.

As a side note, the semantic web is a subset of Web 3.0, but I’m out of breath and will save that for another posting.

This entry was posted on 24. July 2008 at 11:00 and is filed under Industry Buzzwords, Technical Focus. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.