Hello Michael,
On 2011-07-22 10:59, Michael Hausenblas wrote:
Frans,
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.
Sorry, you lost me here. Did you curl it or how did you get your
findings?
Yes, I tried curl. I have just tried it again:
curl -H "Accept: application/rdf+xml"
http://dbpedia.org/void/data/Dataset.rdf
The response seems to be different from yesterday. Yesterday I
immediately got an error message. I am afraid I don't have the exact
message any more. The response I get now is different, a transaction
time out, which I get after waiting a bit.
Probably this is just a temporary situation and besides the point too.
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)?.
<http://lod-cloud.net/dbpedia> a void:Dataset;
foaf:homepage <http://dbpedia.org/>;
Says everything, or?
Well, let me see...
First of all, please know that I am new to Linked Data and RDF, so there
is a chance I don't fully understand everything.
I think what it says is that there is a thing identified by the URI
http://lod-cloud.net/dbpedia, that that thing is a dataset and that its
home page is http://dbpedia.org/.
So, does this mean that the URI of the dataset (DBPedia) is
http://lod-cloud.net/dbpedia??
Sorry if I seem to be stupid, it is not my intention.
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.
Agreed. But it's not a 'trick'. It's called a standard.
Sorry about that!
Regards,
Frans
Cheers,
Michael
--
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 22 Jul 2011, at 09:42, Frans Knibbe wrote:
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
