Re: Semantic Web: Beyond Metadata

From: Robert Coyote (
Date: Fri Oct 19 2001 - 08:39:26 MDT

WHat role could XML play in this?
----- Original Message -----
From: "J. R. Molloy" <>
To: <>
Sent: Friday, October 19, 2001 6:37 AM
Subject: Semantic Web: Beyond Metadata

> Smarter Web Update
> You can't have a Semantic Web without metadata, but metadata alone won't
> suffice. The metadata in Web pages will have to be linked to special
> that define metadata terms and the relationships between the terms. These
> of shared concepts and their interconnections are called "ontologies."
> Say, for example, that you've made a Web page listing the members of a
> faculty. You would tag the names of the different members with metadata
> such as "chair," "associate professor," "professor" and so on. Then you'd
> the page to an ontology-one that you created yourself or one that someone
> has already made-that defines educational job positions and how they
relate to
> each other. An appropriate ontology would in this case define a chair as a
> person, not a thing you sit on, and it would indicate that a chair is the
> senior position in a department.
> By defining the relationships between terms, ontologies can then be used
> applications to infer new facts. Suppose you have created a Web page that
> teaches schoolchildren about condors, and have added metadata to the
> You could link to an ontology (or more likely, several ontologies) that
> the various terms and their relationships: "California condor is a type of
> condor from California." "Condor is a member of the raptor family." "All
> raptors are carnivores." "California is a state in the United States."
> "Carnivores are meat eaters." By using both metadata and ontologies, a
> engine or other software agent could find your condor site based on a
> request for "carnivores in the U.S."-even if your site made no mention of
> carnivores or the United States.
> Because ontology development is a big undertaking, it's likely that site
> creators will link to third-party ontologies. Some will be free, others
> be sold or licensed. One issue that will have to be confronted: just as
> dictionaries and atlases, political and cultural bias will creep into
> ontologies. A geography-based ontology maintained by the Chinese
> for instance, would probably not define Taiwan as a "country."
> But that hardly impedes the vision. As the World Wide Web Consortium
> to develop standards and technologies for the Semantic Web, hundreds of
> organizations, companies and individuals are contributing to the effort by
> creating tools, languages and ontologies.
> One major contributor is DARPA-the folks responsible for a great deal of
> technology behind the Internet (see "DARPA's Disruptive Technologies," TR
> October 2001). These days, DARPA is contributing tens of millions of
> to the Web consortium's Semantic Web project and has developed a semantic
> language for the U.S. Department of Defense called DARPA Agent Markup
> that allows users to add metadata to Web documents and relate it to
> ontologies. University of Maryland computer science professor Jim
> was until August manager of the DARPA program-has been working closely
> Berners-Lee and Miller to ensure consistency with the consortium's
> Last December, Hendler announced the creation of a language that combines
> DARPA Agent Markup Language's capabilities with an ontology language,
> developed in Europe, called OIL (which stands for both Ontology Inference
> Layer and Ontology Interchange Language).
> A developer of this new language, University of Manchester lecturer Ian
> Horrocks, also advises the World Wide Web Consortium on the Semantic Web.
> January, he cofounded a company called Network Inference to develop
> that uses ontologies and automated inference to give Semantic Web
> to existing relational databases and large Web sites. Recently, an Isle of
> Man-based data services company called PDMS began using Network
> technology to add Semantic Web capabilities to corporate databases. Dozens
> other companies, from Hewlett-Packard to Nokia, are contributing to
> Web development
> Too Much, Too Late?
> Miller believes the seamless flow and integration of information resulting
> from these moves will make it possible to process knowledge in a way "that
> solves problems, brings people closer and spurs on new ideas that never
> happen before." Others, though, are not so optimistic about the Semantic
> "It's rather ambitious," says R. V. Guha, who led development of the Web
> consortium's Resource Description Framework efforts in the late 1990s.
> framework is an essential tool for describing and sharing metadata.) "It
> be nice if such things existed," he says, "but there are some really hard
> research problems that need to be solved first."
> One issue concerns inference. The time it takes a computer to draw new
> conclusions from data, metadata and ontologies on the Web increases
rapidly as
> rules are added to a system. Inference falls into the same category as the
> classic "traveling-salesman problem" of planning the shortest route
through a
> number of cities. It's not hard to figure out the best of all possible
> when you're dealing with just a very few locations. But when you get up to
> only 15 cities, there are more than 43 billion possible routes. The same
> of runaway situation exists for inference, where brute-force searches for
> answers could lead to time-wasting paradoxes or contradictions.
> And even if Berners-Lee and his cohorts meet the technical challenges,
> won't be enough for the Semantic Web to click into place. There is a big
> question as to whether people will think the benefits are worth the extra
> effort of adding metadata to their content in the first place. One reason
> Web became so wildly successful, after all, was its sublime ease of
> "The Web today is the simplest, most primitive form of hypertext," says
> Sun Microsystems Distinguished Engineer Jakob Nielsen, cofounder of the
> Nielsen Norman Group, a Web design firm in Fremont, CA. "And that's why it
> so easy to implement; that's why everybody could...start putting up their
> Web pages; that's why the Web is so big." However, while most people may
> comfortable doing simplistic editing, such as marking a text as "bold,"
> Nielsen points out, "They cannot do semantic editing, where they say,
'This is
> the author's name,' or 'This is the name of people I'm quoting.'"
> Of course, such pessimism may be ignoring recent history. Not so long ago,
> notion of millions of people learning to write HTML code seemed
> far-fetched-yet that's exactly what happened. Still, the hurdle of
creating a
> Semantic Web will be higher. People can use HTML any way they want. They
> commonly use tables for nontabular purposes, for instance, and slap on the
> "subhead" tag merely to apply boldface. These kluges and shortcuts usually
> have only cosmetic consequences. But the same type of fudging-say, by
> employing "bibliography" tags to list a DVD collection-could make a page's
> metadata unusable.
> The fact that metadata wasn't implemented right from the Web's start could
> also make it harder for the Semantic Web to gain acceptance. One
> tough skeptic is Peter Merholz, cofounder of Adaptive Path, a San
> Francisco-based user experience consultancy. "This stuff has to be baked
> from the beginning," says Merholz, who calls the Semantic Web "an
> academic pursuit" with little bearing on society. "The Semantic Web is
> a lot of hype simply because Tim Berners-Lee-the inventor of the World
> Web-is so interested in it," he says. "If it were just some schmuck at
> university in Indiana, nobody would care."
> Initial Threads
> Even Berners-Lee admits that the path to the Semantic Web may be a bit
> than that to the World Wide Web. "In a way we don't need to move too
fast," he
> says, "because the theory people need to look at it to make sure we're not
> crazy, and other people need to check out the ideas in practice before
> picked up and used too extensively."
> When asked to peek into his crystal ball, the evangelist of exchangeable
> predicts that some of the Semantic Web's first commercial applications
> aim to integrate the different information systems that typically coexist
> large organizations. (Wouldn't it be nice to take care of business at the
> motor vehicle department or hospital without having to fill out a
> largely redundant forms? The Semantic Web can help here.)
> And even though the Semantic Web still resides chiefly on the drawing
> you can see hints of its power on some existing Web sites. Consider
> Technologies' search engine that crawls thousands of news sites several
> a day, making it a favorite for news junkies. Moreover's software agents
> been programmed to look at the font tags (the HTML labels that tell Web
> browsers how large or small to make the text appear on the screen) to
> determine whether or not a particular page is a news story. If a Moreover
> agent finds a string of six to 18 words tagged as large type near the top
of a
> page, it will assume it is a headline and place it in a database. Of
> since the agent is only making a guess, sometimes it selects a page that
> news after all. So Moreover has to apply additional filtering to get rid
> pages that don't contain articles.
> That's still a far cry from the ultimate goal-but it's a good start. And
> the Semantic Web champions don't pretend to grasp exactly where such steps
> will lead. After all, who predicted or eBay back when
> turned on the switch of the world's first Web server in December 1990?
> But the point is that people want more intelligence from the Web than
> getting-and a growing number of computer scientists share the twinkle in
> Berners-Lee's eye, and the feeling that the Semantic Web holds the answer.
> "It's great," says the inventor of the World Wide Web, "to have that
> grass-roots enthusiasm around again."
> --- --- --- --- ---
> Useless hypotheses, etc.:
> consciousness, phlogiston, philosophy, vitalism, mind, free will, qualia,
> analog computing, cultural relativism, GAC, Cyc, Eliza, cryonics,
> uniqueness, ego, human values, scientific relinquishment
> We move into a better future in proportion as science displaces

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