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Why is RDF so old, complicated, unpopular and still not discarded?

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Re: Why is RDF so old, complicated, unpopular and still not discarded?

#31
post #3

Earlier quoted context omitted.

Not quite. While RDF certainly isn't all that the idealists claim, you can still get some benefit of it without strong AI. Mainly, it provides a consistent model for handling the notion of a "field". Non-RDF apis typically return fielded JSON or XML, the structure of which is only specified within the documentation. In order to integrate two services not originally designed to inter-operate, you have to write lots of…

My claim is that your "generic rules" to govern mapping fields are actually equivalent to hardcoding the names of JSON fields. Instead of seeing "title", and deciding what to do with the data, you see: ... and decide what to do with the data. In both cases, instead of having a machine understand the (semantic) structure of the data, you have a programmer writing a rule. Can you provide a concrete example of where thi…

It seems like the missing piece for you is that RDF is one level of abstraction higher than what you're talking about.

If you're just thinking about parsing data out of the above XML snippet, yeah, of course it's more complicated. But the point of RDF is that you don't think about the serialization format (there's libraries for that). You should be thinking about your data at a higher level of abstraction, at the level of "triples" and "inference rules".

You're expected to use a triples database and an inference engine of some kind, either a library or by rolling your own. If you're not, then I agree, you're not deriving any benefit from RDF. But if you are, then it lets you deal with your data in a more abstract, generalized way that does provide legitimate value for certain use cases.

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#32
post #3

As a preamble, when RDF was conceived, databases drove many sites on the web, but their data tended to only be exposed as HTML, instead of a more machine-friendly format. Now, there are two perspectives on what RDF is. To an idealist, RDF is the universal data format. There are no semantics baked-in, and you can write arbitrary subject -> predicate -> object triplets to express any possible relationship. To an ideali…

Not quite. While RDF certainly isn't all that the idealists claim, you can still get some benefit of it without strong AI. Mainly, it provides a consistent model for handling the notion of a "field". Non-RDF apis typically return fielded JSON or XML, the structure of which is only specified within the documentation. In order to integrate two services not originally designed to inter-operate, you have to write lots of…

You can also publish RDF via JSON: http://json-ld.org/

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#33

Earlier quoted context omitted.

APIs are everywhere, and RDF is nowhere. RDF is hardly ubiquitous, but it's also hardly appropriate to say that it's nowhere. RDFa in particular has seen a big surge in adoption over the last year or two, especially after Google and Yahoo announced that they would start utilizing RDFa. http://tripletalk.wordpress.com/2011/01/25/rdfa-deployment-a...

To continue to play devil's advocate here ... if RDF is just an awkward API, RDFa is just an awkward microformat.

More specifically, it is an extensible microformat. Microformats are practically a subset of RDFa with locked-down ontologies (hCard, hCalendar etc).

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#34
post #11

Hands up anyone who uses RDF (when they could choose to do otherwise)? Anyone? Bueller?

Our CMS user interface is built based on RDFa:

http://bergie.iki.fi/blog/using_rdfa_to_make_a_web_page_edit...

The content repository we use also provides RDF storage and querying:

http://www.midgard-project.org/updates/midgardcr_10-12-hrung...

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#35
post #22

Earlier quoted context omitted.

Hey, I really wish that "subject/predicate/object" was all that RDF was, but I'm afraid it's a good deal more: RDF Syntax: http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/ RDF Schema: http://www.w3.org/TR/2004/REC-rdf-schema-20040210/ RDF Semantics: http://www.w3.org/TR/2004/REC-rdf-mt-20040210/ (Those are all current W3C standards)

I agree that a lot of the standards surrounding RDF are ugly. I've always particularly disliked the RDF-as-XML serialization, which took two fairly simple ideas (triples and XML) and combined them into a complex mess. This is why I always hate parsing RSS 1.0. Also, the full generality of OWL just confuses me: It seems to be Prolog done badly. But just as with XML, it's possible to ignore the cruft (XQuery, XLink, XM…

Agreed. You can get all the benefits of RDF while eschewing the stupid parts. Just because something has a spec doesn't mean you have to use it.

The full XML spec, for example, is insanely complicated. But people still derive value from it by utilizing a more or less sane subset.

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#36
I see a lot of RDF bashing. Particularly from the "Web 2.0" crowd. It has warts, no doubt (is anything borne of the human mind without warts?), but it also has its strengths. A lot of people say it is a failed technology but it's less the failure of the technology and more a failure of the people saying so to properly understand what it can/does do.

Is that a failure of the technology? Because most people don't understand what they would use it for or how they would apply it? I don't think so. I think the claims that it would change the web were high-flown. I also think its creators did a bad job of explaining it. However, you'll find the people that do understand it and have a domain in which it is clearly applicable - love it.

One of my friends works for the library at UCSD and they use RDF, RDFS, and OWL-DL extensively - I couldn't even imagine doing what she does with the library's book ontology using JSON (as some have proposed replace XML and it's vocabularies, even with a JSON "schema" language). I have another friend working for a biotech company - and he uses it there, extensively. These are only two examples and it excludes the other web projects and companies out there that also use it and it's higher level vocabularies/ontologies (UMBEL, etc...).

Is it a failure for the web? (a topic in another thread a few days ago) I don't think it is, I think it is a failure on the part of developers to understand it and apply it (Drupal has applied it).

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#38
post #11

Hands up anyone who uses RDF (when they could choose to do otherwise)? Anyone? Bueller?

I don't personally, right now, but I have a friend working for UCSD that uses RDF, RDFS, and OWL-DL quite a bit with their ontology there. I also have a friend in biotech that uses it a lot.

I've used it for past projects (NDA, can't really talk much about it here) in the knowledge representation and inference domain.

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#39
post #32
post #3

Earlier quoted context omitted.

Not quite. While RDF certainly isn't all that the idealists claim, you can still get some benefit of it without strong AI. Mainly, it provides a consistent model for handling the notion of a "field". Non-RDF apis typically return fielded JSON or XML, the structure of which is only specified within the documentation. In order to integrate two services not originally designed to inter-operate, you have to write lots of…

You can also publish RDF via JSON: http://json-ld.org/

btw, that is also an issue which is addressed by the newly revived RDF working group - http://www.w3.org/2001/sw/wiki/index.php?title=RDF_Core_Work...

Re: Why is RDF so old, complicated, unpopular and still not discarded?

#40
post #23

Many people here are answering the question of why RDF sucks, but that was not the question asked. The question is why this suckage has still not managed to bury the technology. There is a very frequent problem people suffer from, which is mistaking goals for results. When you start looking for it, you'll see it a lot. A new open source NoSQL database will pop up, post a long list of goals ("Fastest performance, main…

Great point. I think another example is XML. It was going to free us from proprietary, binary data formats by making everything nice and understandable pointy brackets. Everyone understands things written in pointy brackets, right?

The reality is that we got OOXML and ODF, which are so enormously complex that no piece of software except Microsoft Word and OpenOffice could hope to fully implement them. If there was an ACID3 test for either it would be fully clear how bad and non-interoperable the situation is. We got XHTML, which turned out to be a horrible idea ( http://diveintomark.org/archives/2004/01/14/thought_experime... ) and is now abandoned. We got XML schema, because everyone realized that when you have structured data you want data types, instead of everything being just text.

And because XML seduces you into thinking it's much simpler than it actually is, people write their own parsers and generators all the time that have no hope of knowing what to do with a CDATA section, and you get parsers that will fail if the whitespace isn't just exactly right. The whole thing is a giant farce.

Just like you say, people got excited about the promise of XML. This is the perennial problem when people try to create standards in an area that doesn't actually have any compelling implementations yet. Good standards refine and codify existing practice. Bad standards try to invent something and standardize it at the same time.

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