W3C home > Mailing lists > Public > public-lod@w3.org > February 2013

Re: Content negotiation for Turtle files

From: Richard Light <richard@light.demon.co.uk>
Date: Wed, 06 Feb 2013 15:00:37 +0000
Message-ID: <51127015.2020207@light.demon.co.uk>
To: public-lod@w3.org

I'm more than happy for Turtle to have a place in the LD ecosystem. My 
concern is the suggestion that it should become seen as the primary/the 
only delivery format for Linked Data resources such as www.lingvoj.org.

Also, like you, I'm not particularly impressed by massive dumps of 
low-quality data.  In my area of interest (cultural history) what we 
need are reliable sources of data which is sufficiently richly 
structured to be useful.  This usually means they need to be more 
structurally complex than a simple list of properties for an entity (the 
"dbpedia fallacy").

One issue that Turtle will need to address (it may do so already) is 
software support for free-hand data entry.  While the format is 
seductively simple-looking (well, it is to the likes of us who grew up 
on XML/SGML*) it is very easy to make mistakes.

I followed Kingsley's reference to his file space (see his separate 
reply) and grabbed the file jordan.ttl. It contains variations in 
spelling which will mean that some predicate - subject links will fail 
(e.g. New England Patriots), as will one sameAs link (USA). There is (I 
guess) an intended link from USA to N. America, but again this won't fly 
because USA's continent property is expressed as a string.  If case 
matters, most of the sameAs references won't work.  The properties 
(predicates) are all local to the document and none of them is defined.  
Integer values are typed as strings. Two of the dates are wrong (e.g. 
Sept 31 783).  This is not to criticise Kingsley's typing, but rather to 
point out that if you are encouraging users to hand-type resources which 
are to be interpreted as data, then they are going to need some software 
support if they are not going to be mightily let down by the whole 
process.  It's a bit like authoring web pages: it doesn't go too badly 
if you're working in a rich edit box and don't have to add HTML markup 


* the Turtle tyro might disagree, on being asked to type e.g.:
:Championships "3 (2001,2003,2004)"^^xsd:string ;

On 06/02/2013 13:30, Bernard Vatant wrote:
> Thanks Kingsley!
> Was about to answer but you beat me at it :)
> But Richard, could you elaborate on this view that hand-written and 
> machine-processible data would not fit together?
> I don't feel like "people are still writing far too many Linked Data 
> examples and resources by hand". On the opposite seems to me we have 
> seen so far too many linked data produced by (more or less dumb or 
> smart) programs, without their human "productors" (so to speak) always 
> checking too much for quality in the process, provided they can 
> proudly announce that they have produced so many billions of triples 
> ... so many, actually, that nobody will ever be able to assess their 
> quality whatsoever :)
> Of course migrating automagically heaps of legacy data and making them 
> available as linked data is great, but as Kingsley puts it, linked 
> data are not only about machines talking to machines, it's also about 
> enabling people to talk to machines as simply as possible, and the 
> other way round. That's where Turtle fits.
> Bernard
> 2013/2/6 Kingsley Idehen <kidehen@openlinksw.com 
> <mailto:kidehen@openlinksw.com>>
>     On 2/6/13 6:45 AM, Richard Light wrote:
>>     On 06/02/2013 10:59, Bernard Vatant wrote:
>>>     More ??? Well, I was heading the other way round actually for
>>>     sake of simplicity. As said before I've used RDF/XML for years
>>>     despite all criticisms, and was happy with it (the devil you
>>>     know etc). What I understand of the current trend is that to
>>>     ease RDF and linked data adoption we should promote now this
>>>     simple, both human-readable and machine-friendly publication
>>>     syntax (Turtle). And having tried it for a while, I now begin to
>>>     be convinced enough as to adopt it in publication - thanks to
>>>     continuing promotion by Kingsley among others :)
>>>     And now you tell me I should still bother to provide n other
>>>     formats, RDF/XML and more. I thought I was about to simplify my
>>>     life, you tell me I have to make the simple things, *plus* the
>>>     more complex ones as before. Hmm.
>>     Well I for one would make a plea to keep RDF/XML in the
>>     portfolio. Turtle is only machine-processible if you happen to
>>     have a Turtle parser in your tool box.
>>     I'm quite happily processing Linked Data resources as XML, using
>>     only XSLT and a forwarder which adds Accept headers to an HTTP
>>     request. It thereby allows me to grab and work with LD content
>>     (including SPARQL query results) using the standard XSLT
>>     document() function.
>>     In a web development context, JSON would probably come second for
>>     me as a practical proposition, in that it ties in nicely with
>>     widely-supported javascript utilities.
>>     To me, Turtle is symptomatic of a world in which people are still
>>     writing far too many Linked Data examples and resources by hand,
>>     and want something that is easier to hand-write than RDF/XML.  I
>>     don't really see how that fits in with the promotion of the idea
>>     of machine-processible web-based data.
>>     Richard
>>     -- 
>>     *Richard Light*
>     If people can't express data by hand we are on a futile mission.
>     The era of over bearing applications placing artificial barriers
>     between users and their data is over. Just as the same applies to
>     overbearing schemas and database management systems.
>     This isn't about technology for programmers. Its about technology
>     for everyone. Just as everyone is able to write on a piece of
>     paper today, as a mechanism for expressing and sharing data,
>     information, and knowledge.
>     It is absolutely mandatory that folks be able to express triple
>     based statements (propositions) by hand. This is the key to making
>     Linked Data and the broader Semantic Web vision a natural reality.
>     We have to remember that content negotiation (implicit or
>     explicit) is a part of this whole deal.
>     Vapour was built at a time when RDF/XML was the default format of
>     choice. That's no longer the case, but it doesn't mean RDF/XML is
>     dead either, its just means its no longer the default. As I've
>     said many times, RDF/XML is the worst and best thing that ever
>     happened to the Semantic Web vision. Sadly, the worst aspect has
>     dominated the terrain for years and created artificial inertia by
>     way of concept obfuscation.
>     If your consumer prefers data in RDF/XML format then it can do one
>     of the following:
>     1. Locally transform the Turtle to RDF/XML -- assuming this is all
>     you can de-reference from a given URI
>     2. Transform the Turtle to RDF/XML via a transformation service
>     (these exist and they are RESTful) -- if your user agent can't
>     perform the transformation.
>     The subtleties of Linked Data are best understood via Turtle.
>     -- 
>     Regards,
>     Kingsley Idehen	
>     Founder & CEO
>     OpenLink Software
>     Company Web:http://www.openlinksw.com
>     Personal Weblog:http://www.openlinksw.com/blog/~kidehen  <http://www.openlinksw.com/blog/%7Ekidehen>
>     Twitter/Identi.ca handle: @kidehen
>     Google+ Profile:https://plus.google.com/112399767740508618350/about
>     LinkedIn Profile:http://www.linkedin.com/in/kidehen
> -- 
> *Bernard Vatant
> *
> Vocabularies & Data Engineering
> Tel : + 33 (0)9 71 48 84 59
> Skype : bernard.vatant
> Blog : the wheel and the hub <http://blog.hubjects.com/>
> --------------------------------------------------------
> *Mondeca*****
> 3 cité Nollez 75018 Paris, France
> www.mondeca.com <http://www.mondeca.com/>
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> ----------------------------------------------------------
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*Richard Light*
Received on Wednesday, 6 February 2013 15:01:07 UTC

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