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Re: Is it best practices to use a rdfs:seeAlso link to a potentially multimegabyte PDF?, existing predicate for linking to PDF?

From: Phil Archer <phil.archer@talis.com>
Date: Thu, 13 Jan 2011 12:32:16 +0000
Message-ID: <4D2EF0D0.5030806@talis.com>
To: Vasiliy Faronov <vfaronov@gmail.com>
CC: Martin Hepp <martin.hepp@ebusiness-unibw.org>, nathan@webr3.org, Tim Berners-Lee <timbl@w3.org>, Toby Inkster <tai@g5n.co.uk>, Peter DeVries <pete.devries@gmail.com>, public-lod@w3.org
Hi Vasiliy,

I think it comes down to the application. Whenever you dereference a 
URI, your application is almost certainly going to want some types of 
content and not others. You're bound to do various bits of sniffing and 
testing to see whether what you're going to get back is something you 
can process/use. If you follow an rdfs:seeAlso and get back something 
that you can use, whatever format its in, well, use it. What I'm 
concerned about is the implication that, S rdfs:seeAlso O implies that O 
is RDF that somehow doesn't need to be tested before you throw it at a 
parser. That seems dangerous at best.

Now, things like foaf:isPrimaryTopicOf and other predicates may well be 
better choices than rdfs:seeAlso for linking to non-RDF sources, but to 
err is human. As more people publish triples, be they in RDFa, Turtle 
RDF/XML or whatever, there will be errors and we'll have to handle them. 
What I would feel very uncomfortable with is the idea that if you 
include S rdfs:seeAlso O and O is not RDF then that action alone might 
be seen as meaning the data is invalid - which I think is way too strong 
an inference to make.


On 13/01/2011 11:36, Vasiliy Faronov wrote:
> On Чтв, 2011-01-13 at 11:04 +0000, Phil Archer wrote:
>> Describing a URI with further triples is good, nothing wrong with that,
>> but to use that to decide whether or not to dereference an rdfs:seeAlso
>> URI means looking for a description of the linked resource and then
>> acting accordingly. That sounds like a relatively heavy bit of
>> processing that HTTP kind of takes care of for you.
> Phil, how then do you propose to deal with the following:
> - RDFa
> - web servers that (in full compliance with the spec[1]) ignore the Accept
>    header and just send 200 with the only representation they have (try
>    HEAD http://dev.w3.org/html5/spec/Overview.html with Accept:
>    application/rdf+xml, pay attention to the Content-Length returned)
> [1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.7


Phil Archer
Talis Systems Ltd
Web: http://www.talis.com
Tel: +44 1473 434770
Twitter: philarcher1
LinkedIn: http://uk.linkedin.com/in/philarcher
Personal: http://philarcher.org
Received on Thursday, 13 January 2011 12:32:50 UTC

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