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RDF and OWL Are W3C Recommendations
J1 writes "The World Wide Web Consortium today released the Resource Description Framework (RDF) and the OWL Web Ontology Language (OWL) as W3C Recommendations. RDF is used to represent information and to exchange knowledge in the Web. OWL is used to publish and share sets of terms called ontologies, supporting advanced Web search, software agents and knowledge management. Read the press release for the full list of twelve documents, read the testimonials, and visit the Semantic Web home page."
...you might be interested in a new project hosting site which was just opened - SemWebCentral. It already hosts several DAML tools, including ObjectViewer, the beginnings of an OWL plugin for Eclipse, and various others.
The developers and end users will always ultimately determine what is most popular.
Shirky's peice on the Semantic Web is far below his normal quality. It's poorly researched and poorly considered. (Speaking as someone misquoted in the article...)
For good responses see Peter Van Dijck or Paul Ford.
RDF is actually quite usefull and is used when making extensions for FireFox/Mozilla among other things. Be sure to check out the RDF validator here as it can save you time.
It will be very interesting to see how RDF/XUL stands up against XAML.
Go here for teh [sic] funny.
It's legal. Sometimes alternate text is inappropriate for text browsers. If I have multiple images that make up my logo, for example, it would be approriate to only give one the logo text, and set the others to "". You need the alt, but you don't need to have it equal text.
ALT tags are for the most part used for screen readers. Unnecessary images, used just to enhance the look of the page are often given alt="" values so that the screen reader will skip the image entirely (ie: read nothing instead of saying "image foo.jpg is here with no alt tag").
A lot of RDF out there is in FOAF and RSS 1.0 vocabularies. Increasingly, people use to link RDF files, which makes it possible to have RDF crawlers ("scutters") harvest RDF from the web. I have an RDF aggregator service running that crawls the semantic web. There's a lot of useless broken RDF out there, so if you put RDF on your web site please use W3C's RDF Validator to check for valid RDF.
Microsoft didn't have people active in either Working Group. They didn't fund this any more than any other W3C (Full) Member.
Surely it's about time for Slashdot to go XHTML+CSS?
Yes, as previously discussed here.
Okay, I thought those were relatively pleasant reads, which can be a plus. (And I wanted to say something fast, before slashdot buried any response I might make...)
My actual response at the time is brief and chatty. The response from Dan Brickley is also short and sweet. Neither of us felt it was worth the time to reply point-by-point.
The "misquoting" is to suggest that my "how you buy a book on the Semantic Web" sketch should possibly cause Jeff Bezos to lose sleep. I was trying to explain an experimental protocol in a way I hoped my grandmother could understand (seriously!) and Shirky thinks I'm sketching out Amazon's doom? I don't expect the Semantic Web to doom anyone but folks who want to keep data exchange laborious.
Don't know if the AC will check on this later or not, but the point is that you never want a screen reader saying that. You want to have it spit out useful information (ie: Slashdot image in the upper left, "Welcome to Slashdot") or nothing at all.
If you've ever used clear gifs to space out a page just so, you've hit an area where this is important. You don't want the screen reader spitting something out for an image that the sighted can't even see. What would be the point?
In the W3C page, the 8 alt="" are all little triangle icons, that just sort of indent the text. Does a person who is blind need to hear "Triangular Icon" or "image right.gif is here with no alt tag"? I can't really think of a case for it.
The OWL sense of "ontology" is the second sense, if you read "theory" in the formal (computer science/mathematical logic) sense.
That is, an OWL ontology tells readers (especially computers) what kinds of things exist and what kinds of relationships they can have to each other.
Some of the OWL specs are actually pretty readable. Try starting with the OWL Overview. (Others, like OWL Semantics, are... more challenging.)
And most of the work is already done. What are they waiting for?
See the OWL Faq
It says: Q. What does the acronym "OWL" stand for?
A. Actually, OWL is not a real acronym. The language started out as the "Web Ontology Language" but the Working Group disliked the acronym "WOL." We decided to call it OWL. The Working Group became more comfortable with this decision when one of the members pointed out the following justification for this decision from the noted ontologist A.A. Milne who, in his influential book "Winnie the Pooh" stated of the wise character OWL:
"He could spell his own name WOL, and he could spell Tuesday so that you knew it wasn't Wednesday..."
nice to see a working group with a sense of humor...
Personally I find it hard to work with RDF/XML since it can get kind of unreadable. I've found this primer on n3 helpful. n3 is a simpler way to write RDF, which makes the triple structure a little more obvious.
A fun place to start in RDF is making a foaf page. Foaf is the friend of a friend vocabulary. If you search for foaf in google you should find stuff to help you start with it. This lets you track things like degrees of seperation between people.
You can write OWL markup that describes the content of your webpage, but this is somewhat harder to do (there are some graphical tools that would help), and less useful right now. There aren't many tools that make use of/display random OWL markup associated with a web page.
More useful for a small webpage might be including dublin core metadata (should have no problem searching for their homepage either) about the author, title, etc. of each page. The dublin core initiative provides info about how to do this.
God does not play dice - Einstein
Not only does God play dice, he sometimes throws them where they
There are some interesting threads in discussing Shirkey to be found over at W3C:- intere st/2003Nov/0047.htmlr ch
http://lists.w3.org/Archives/Public/www-rdf
or search for Shirkey in the archive
http://www.w3.org/Search/Mail/Public/sea
> I'd be thrilled if they even just went to valid HTML
I'd be thrilled if they fact-checked and wrote some of their own stories for a change.
An Ontology is supposed to tell you what things are (what things there are) and how those things are related.
OWL and RDF schemas are ontologies in the philosophical sense in that they define a set of entities and relations which allow you to make meaningful inferences from assertions framed in terms defined by the ontologies in question. An Ontology defines the categories and relations that make up a world.
Ontologies are not themselves information (except in the trivial sense) but rather structures which allow agents (human or machine) to make sense of information.
To use an extremely basic example, let's say you have an Ontology for all things connected to selling snacks, you would have categories for Snacks, Owners, Currency and Transactions. Each of those categories might have sub categories (Snacks:hot,Snacks:cold) and each Category will have constraints on the relationships it can have. You would also have entries for the relations that can exist (Whole-part, owns, consumes). As you can see even a very basic ontology quickly grows to be quite complex.
I'd be thrilled if they fact-checked and wrote some of their own stories for a change.
Even reading the original article that a story refers to would be progress.
I know, the fact that somebody already did all the work for them makes their lack of progress even more inexcusable.
About the only hard thing about the whole exercise (other than finding a way to run Internet Explorer to test it for the various bugs in its CSS implementation) is validating or correcting user comments to make sure they will be valid markup once inserted in the main page. This isn't rocket science, I think tools like xmllint do this for free.
Even XHTML 1.1 isn't that hard to comply with, it's hardly any different to XHTML 1.0 except in all the places which Slashdot shouldn't care about. Come on, we're talking about a news site which bans almost all markup anyway!
HTML 3.2, I spit on your corpse.
As for RDF... it would be useful on Slashdot too, in theory. I guess a web robot could figure out which topic stories are about, but we would need to change our topic categorisation to some sort of standard for the robots to make any sense of it all.
Karma: It's all a bunch of tree-huggin' hippy crap!