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RDF For Desktop Metadata?
claes writes "There is an article "Metadata for the desktop" that suggests that RDF should be used to describe data in desktop environments. This is an interesting idea. RDF is already used by Creative Commons to attach license metadata to its works. Mozilla also supports it.
RDF was designed for the web, but can it also find its way to the desktop? And what metadata is most important to describe?"
Why don't slashdoters define what meta-data is in the first place? Google's define: metadata lists not less than 20 definitions. Are we talking about "data about data"?
Why does the document complain about the lack of integration, then mention that Microsoft, Apple, the ReiserFS people, etc. are coming up with solutions, and then adds a completely new one? Shouldn't they just be supporting one Apple's or ReiserFS's efforts?
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
I've heard the NTFS file system is designed to allow the system to add any number of properties (besides the obvious filename, last access time and permissions) to any stored file. This is likely to be exploited by Longhorn, which is planned to be capable of appending metadata to newly created files (for example, if you download a file from the Internet, the system would likely append a Originated-From-URL property to it).
What I wonder is, is there any filesystem in the FOSS world that supports something like this, or are there plans to make it supported before 20??, when Longhorn hits the stores? I see this as a critical feature that must be made available by non-Windows OSes.
Score: i, Imaginary
I'm mostly wondering if the new Spotlight feature of MacOS X 10.4 is going to be based on this, or a proprietary technology. I've been itching for cross-platform metadata file support for years now...
Danny Ayers has some interesting discussion on his blog about winfs and rdf. There's also discussion of Jon Udell's Questions about Longhorn.
A group at MIT is using RDF for an integrated data management system. It's sorta like Outlook (or Kontact, if you prefer ;-) on steroids. It's called Haystack.
I have to say, their ideas are intriguing, but after using it... I think the big shortcoming is that it's tough to come up with a generalized user interface for manipulating any data thrown at it. Haystack tries at this, and I think, fails at providing any kind of cues or context that tells you what your are dealing with. In Haystack, every task and piece of information you deal with looks very much like every other piece of data, because, as a design choice, Haystack every piece of data has the same rank as every other piece of data.
Having different applications for different types of data usually make sense, if only to limit the amount of options presented to the user so they can make an intelligent decision about what action they want to perform. See this article on Slashdot about how users need limited since it makes decision-making too difficult psychologically.
Inevitably, discussions around RDF and metadata always devolve into hand-wavy discussions on how the computer will be able to "magically" do smart things based on the metadata. But it really isn't magic and it isn't automatic at all. Equivalencies and mappings have to be created by humans along with the rules about what to do.
RDF uses many concepts from AI research. Anybody who has read about this branch of computer science knows that the discipline has pretty much given up on creating AI in the 'sci-fi' sense as an impractical dream. That's what makes the Loebner prize so controversial. I don't expect that computers will be intelligent enough able to relieve users of too much of the burden in assigning metadata.
RDF is a promising approach, but if you read the article, it makes a lot of assumptions about what needs to happen to make the benefits real. Among them are establishing standards for what metadata fields apply to different types of objects: photos, people, music, etc. That kind of standardization won't happen overnight, if at all.
The computer also needs to know what to do when it encounters that kind of data. The article mentions MIME and browsers and, in effect, says the browser can make a rational decision even if it hasn't seen a particular MIME type before. That isn't really true.. you have to install a plugin that tells the browser what to do, or have a registry that someone has put together where the browser can install the right plugin at the right time.
That said, KDE's unification of contact information and passwords does show some of the promise of metadata efforts. And Apple's Spotlight looks like a good solution as far as it goes. I guess I'm just trying to make the point that the magic of metadata needs to be taken with a fairly large hunk of salt.
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In X-Windows the client serves YOU!
But when I tried to publish one article at Kuro5hin, the RDF code, which took the form of HTML comments, was displayed literally in the visible body of my article. That is, all the tags had been turned into entities so the tags appeared literally in the rendered text.
I think Kuro5hin's Scoop content management system doesn't permit HTML comments. Maybe it's not trying to suppress comments, but it didn't occur to scoop's developers to allow them.
RDF on the web would likely be much more popular if one could count on publication sites allowing it in the submitted markup.
Another problem I had is that Creative Commons' recommended way to apply a license to a web page is not permitted by any of the community sites I frequent. CC-licensed web pages usually have a small banner that links to the license text. But for obvious reasons, sites like Slashdot and Kuro5hin don't permit images in article or comment submissions.
The result is that, even for the copies of my articles on my own website, I use neither RDF nor the CC banner, because I want to make it easy for others to copy my CC-licensed articles to site that don't permit RDF or graphics.
The way I apply the license is the much-less-cool method recommended for plain text files. I have the following text appear in the body of my articles:
Request your free CD of my piano music.
I noticed the article made no mention of Pike (also the name of a fish - see language logo). Pike's a fine C-like scripting language ...that I know extremely poorly myself, but anyway..
From Pike's official homepage (at the University of Linkoping, Sweden):
Worth downloading and checking out for other reasons than "just" RDF & OWL. Free software, available under LGPL, GPL, and MPL (Mozilla Public License).
668.5
the fact that Mac OS X uses .plist files to represent creator code and application information in .APP bundles.
if you had RTFA, or even read anything in the last 20 years, you would probably know that XML != RDF. there is a XML implementation of RDF, called (duh) rdfxml, but that's far from the only way to describe RDF data. I have to agree though that rdfxml is one of the worst ways to do RDF.
have a look at N3 or ntriples for starters.
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