[whatwg] RDFa

Henri Sivonen hsivonen at iki.fi
Sat Aug 23 06:38:39 PDT 2008

On Aug 23, 2008, at 02:43, Ben Adida wrote:

> Why would you reinvent URIs in a way that they can't be de-referenced?

To avoid having misleading affordances.

> We want one parser, with variability and innovation in the  
> vocabulary definition only.

Having one parser seems appealing compared to using the native  
mechanisms of each of HTML (<meta>, <link>), PDF (document information  
dictionary), PNG (tEXt chunk), etc. at first, but the vision that  
tools handle this all when you remix culture already requires the  
tools to support reading and writing the file formats they remix. When  
you already have format-native key-value read/write capability, the  
ability to build and mine RDF *graphs* becomes an additional burden.

>> What barrier is there to building reusable vocabularies?
> The follow-your-nose principle is missing, which is fairly essential  
> for
> discovering the meaning of vocabularies (partially automatically,  
> not by
> doing a Google search.)

The partial automation with RDFa doesn't go very far. If a program  
automatically dereferences http://creativecommons.org/ns# and parses  
the result as RDFa, the program now has a human-readable string for  
each property--not exactly something that the program can act on  
further without human help.

Also, tools that automatically follow their nose with RDFa will  
perform a DDoS attack on hosts whose names appear in *other* namespace  
URIs that were meant as mere identifiers.

>>>> The failures of the past have had little to do with the syntax or
>>>> expression mechanisms. They have to do with users simply not  
>>>> caring.
>>> They don't care because there are no useful tools for them to care
>>> about
>> "The tools will save us" is about as big a warning sign as you can  
>> get.
> I didn't say that. I said that when you preclude good tools, then  
> you're
> doomed. Tools are not sufficient, but they often play an important  
> role.

For the RDF vision to work, the entire culture remixing toolchain has  
to preserve digital rights management metadata.

>> Sure, like I said, we have lots of very versatile extension  
>> mechanisms
>> already.
> And as I keep pointing out, the syntax enabled by the existing  
> extension
> mechanism is not generic enough for the classes of data folks need to
> express. With RDFa, they would be generic enough.
>>>> For example, in PDF, do people *really* need all this cruft:
>>> People don't need it, machines do.
>> No they don't. Again, consider the RDF-blobs-in-HTML-comments  
>> stuff. The
>> machines don't need the RDF cruft around the metadata, they just  
>> need the
>> license URI. Tools that process those license statements at scale  
>> don't do
>> any RDF processing at all.
> But... I already told you that we're trying to do more than just the
> license statement.

Attribution URL and Attribution name could be additional key-value  
entries in the document information dictionary. (And attribution name  
could default to the standard entry for "Author".)

Henri Sivonen
hsivonen at iki.fi

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