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Re: Dataset URIs and metadata.

From: Frans Knibbe <frans.knibbe@geodan.nl>
Date: Fri, 22 Jul 2011 10:42:45 +0200
Message-ID: <4E293805.5010004@geodan.nl>
To: public-lod@w3.org
On 2011-07-21 16:27, Michael Hausenblas wrote:
>
>> But is this really common practice nowadays? Take DBpedia for 
>> example. What is the URI of the DBpedia dataset? Is it 
>> http://dbpedia.org? That does not seem to resolve to a set of metadata.
>
> Did you have a look at the URI I gave you? I mean 
> http://lod-cloud.net/void.ttl
I had a quick look. But I could not find it. I had a closer look now and 
I see the URI probably is http://dbpedia.org/void/Dataset. I have tried 
it. Redirection to either HTML or RDF seems to be in place. HTML request 
lead to http://dbpedia.org/void/page/Dataset, which shows a table of 
VoID properties. The RDF redirection (to 
http://dbpedia.org/void/data/Dataset.rdf) does not seem to work, I get 
an error.

Apart from the error, somehow this is not what I expected. I assumed 
that the dataset URI is /the/ URI of a dataset. It is the key to all 
other data. If you want something from a dataset, you only need to know 
this URI. So why is the dataset URI hard to find? Why isn't it used when 
references are made to DBpedia? Why isn't it the same as the base URI 
(http://dbpedia.org)?.

Probably VoID metadata/dataset URIs will be easier to discover once the 
/.well-known/void trick (described in paragraph 7.2 of the W3C VoID 
document) is widely adopted.

>
> BTW, some 30% [1] of the LOD cloud datasets are using VoID ...
>
>> Is there a general way of obtaining datasets URIs?
>
> Not to my knowledge. We're working on it in LATC [2] - Keith?
>
> Cheers,
>     Michael
>
> [1] 
> http://www4.wiwiss.fu-berlin.de/lodcloud/state/#data-set-level-metadata
> [2] http://latc-project.eu/
>
> -- 
> Dr. Michael Hausenblas, Research Fellow
> LiDRC - Linked Data Research Centre
> DERI - Digital Enterprise Research Institute
> NUIG - National University of Ireland, Galway
> Ireland, Europe
> Tel. +353 91 495730
> http://linkeddata.deri.ie/
> http://sw-app.org/about.html
>
> On 21 Jul 2011, at 15:19, Frans Knibbe wrote:
>
>>
>> Thanks for the replies. It seems that there is agreement that a 
>> dataset should have a URI and that dereferencing that URI should 
>> return metadata about the dataset. That is good to know.
>>
>> But is this really common practice nowadays? Take DBpedia for 
>> example. What is the URI of the DBpedia dataset? Is it 
>> http://dbpedia.org? That does not seem to resolve to a set of metadata.
>>
>> Is there a general way of obtaining datasets URIs?
>>
>> I can imagine an RDF dataset comprising all known dataset URIs. And 
>> of course that dataset will have a URI itself. Does such a dataset 
>> exist at the moment?
>>
>> Regards,
>> Frans
>>
>>
>> On 2011-07-21 12:35, Frans Knibbe wrote:
>>>
>>> Hello,
>>>
>>> I have just placed a Linked Data dataset online and now I am 
>>> struggling with finding the best way to publish the metadata of the 
>>> dataset. I wonder if there are best practices for referencing a 
>>> dataset and its metadata, and for linking the two.
>>>
>>> I did find out that using the Vocabulary of Interlinked Data (VoID) 
>>> is a good way to publish the metadata of a dataset. But I still need 
>>> some guidance. I have come up with three questions:
>>>
>>> 1) Is it common practice/recommendable to regard a dataset a 
>>> resource? If it is, then all datasets should have a URI, right?
>>> 2) If having a dataset URI is a good thing, what should be behind 
>>> the URI? Should dereferencing the URI lead to the dataset metadata 
>>> (a VoID file for example)?
>>> 3) If dereferencing a dataset  URI leads to the dataset metadata, 
>>> should there be separate HTML and RDF versions of the metadata? Or 
>>> is it better to have a HTML page with embedded (RDFa) RDF data?
>>>
>>> Thanks in advance for your help,
>>> Frans
>>
>
>
Received on Friday, 22 July 2011 08:43:16 UTC

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