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Re: How do you flag a resource which is not available anymore?

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Mon, 2 Jun 2014 15:22:15 +0200
Message-ID: <CAK4ZFVH8E27KBy2tJUfZ86y6FzEVgwwmiLXKKu+fqkVLR8d+6g@mail.gmail.com>
To: Quentin Reul <Quentin.H.Reul@gmail.com>
Cc: Simon Spero <sesuncedu@gmail.com>, "public-vocabs@w3.org" <public-vocabs@w3.org>
Hi Quentin

The way I understood it, owl:deprecated is more designed to mark elements
in a vocabulary as deprecated, but not the entire vocabulary. Moreover,
owl:deprecated should be used in a controlled versioning workflow, by the
vocabulary publisher herself, and in the best of worlds, it goes with a
dcterms:isReplacedBy (but as said above, this is not unfortunately a very
frequent practice).
Here we deal with URIs which just disappear "puff" in a smoke like URIs do,
by neglect of their owner, hosting not paid, site reorganization whatever.
And we have to make this observation and declaration from outside : the
resource we are speaking about used to live at this URI, but for some non
documented reason it's not there anymore.


2014-06-02 14:45 GMT+02:00 Quentin Reul <Quentin.H.Reul@gmail.com>:

> Hi all,
>
> It may be a bit too simplistic, but OWL2 defines a property
> (owl:deprecated [1]) to mark any entities (classes, properties and
> instances) as deprecated. The range of the property is xsd:boolean. Would
> this not be sufficient for your needs?
>
> Kind regards,
>
> Quentin Reul
>
> [1] http://www.w3.org/TR/2012/REC-owl2-syntax-20121211/#a_deprecated
>
>
> On 2 June 2014 03:17, Bernard Vatant <bernard.vatant@mondeca.com> wrote:
>
>> Simon
>>
>> Thanks for the reference, not yet looked into it in details, but as
>> answered to Ed, we're not looking for an overkill solution :)
>>
>>
>> 2014-05-30 23:13 GMT+02:00 Simon Spero <sesuncedu@gmail.com>:
>>
>> This paper is generally relevant to the semantics, though it doesn't
>>> solve the specific problem:
>>>
>>> Representing and Querying Validity Time in RDF and OWL: A Logic-Based
>>> Approach✩
>>> Boris Motik, Oxford University Computing Laboratory, Oxford, UK
>>>
>>>  http://www.cs.ox.ac.uk/boris.motik/pubs/m12validity-time.pdf
>>>
>>> PROV-O can handle the use case, but has the downside of being PROV-O,
>>> and requiring a few blank nodes (validity is a bit fuzzy).
>>>
>>> http://www.w3.org/TR/2013/REC-prov-o-20130430/#invalidatedAtTime
>>> http://www.w3.org/TR/2013/REC-prov-o-20130430/#Revision
>>>
>>> Also, note that the ontology named by a version IRI is fixed;  if the
>>> IRI becomes impossible to dereference, the cached content should always be
>>> valid;  however, this may not be the case if the base IRI is used.
>>>
>>
>> Indeed! But the use of versionIRI in LOV vocabularies is not a general
>> practice, far from it : See http://bit.ly/1nH1vlq
>> Less than 10% of vocabularies have a owl:versionIRI declaration, and
>> those who use it don't always do it correctly :(
>> More generally the versioning policy is globally a mess ... See
>> http://bit.ly/RWoZUu
>> Very often there is no version number or date whatsoever, or they are not
>> consistent between the documentation and RDF files (you can have one date
>> in the html, another in the RDF/XML file, and yet another one in the Turtle
>> ...
>>
>>
>>> The contents of the LOV-back-machine is as valid as it ever was.
>>>  It is possible that an unversioned ontology  might have changed between
>>> the last capture and the 404
>>>
>>
>> This should not happen if the LOV-Bot, which is tracking changes on a
>> daily basis, does its job properly. But due to content negotiation issues
>> and dozens of other reasons, it is not always the case. And very small
>> changes like corrections of typos can induce the LOV-Bot into uploading of
>> a new version, althogh the formal version information has not changed.
>>
>> But those are known issues that I would not want to blur the simple
>> question at hand : simply providing the information that this URI used to
>> be dereferenceable, but is currently no more, so if you use this vocabulary
>> in your data, the semantics will not be found through the vocabulary URI,
>> but through some version backup etc. We are in terra incognita there ...
>>
>> Bernard
>>
>>
>>>
>>> On Fri, May 30, 2014 at 5:09 AM, Bernard Vatant <
>>> bernard.vatant@mondeca.com> wrote:
>>>
>>>> Hi vocabulers
>>>>
>>>> We have more and more records in LOV of which URIs are 404,
>>>> unfortunately, with no replacing resource whatsoever.
>>>> See e.g., http://lov.okfn.org/dataset/lov/details/vocabulary_dir.html
>>>> etc
>>>> We want to keep the record in LOV, along with backup versions, such as
>>>>
>>>> http://lov.okfn.org/dataset/lov/agg/archives/dir_dir/file_dir_2006-06-27.n3
>>>>
>>>> We want to flag the URI some way, such as some "offlineSince" or
>>>> "validUntil" property, with value a xsd:date. This property would be added
>>>> to the VOAF vocabulary, unless someone knows about an existing property to
>>>> express that. There are various "valid" properties in DC terms and other
>>>> vocabularies, but not sure they capture the expected semantics.
>>>>
>>>> Thanks for any suggestion.
>>>>
>>>> --
>>>>
>>>> *Bernard Vatant *
>>>> Vocabularies & Data Engineering
>>>> Tel :  + 33 (0)9 71 48 84 59
>>>> Skype : bernard.vatant
>>>> http://google.com/+BernardVatant
>>>> --------------------------------------------------------
>>>> *Mondeca*
>>>> 35 boulevard de Strasbourg 75010 Paris
>>>> www.mondeca.com
>>>> Follow us on Twitter : @mondecanews
>>>> <http://twitter.com/#%21/mondecanews>
>>>> ----------------------------------------------------------
>>>>
>>>
>>>
>>
>>
>> --
>>
>> *Bernard Vatant*
>> Vocabularies & Data Engineering
>> Tel :  + 33 (0)9 71 48 84 59
>> Skype : bernard.vatant
>> http://google.com/+BernardVatant
>> --------------------------------------------------------
>> *Mondeca*
>> 35 boulevard de Strasbourg 75010 Paris
>> www.mondeca.com
>> Follow us on Twitter : @mondecanews <http://twitter.com/#%21/mondecanews>
>> ----------------------------------------------------------
>>
>
>


-- 

*Bernard Vatant*
Vocabularies & Data Engineering
Tel :  + 33 (0)9 71 48 84 59
Skype : bernard.vatant
http://google.com/+BernardVatant
--------------------------------------------------------
*Mondeca*
35 boulevard de Strasbourg 75010 Paris
www.mondeca.com
Follow us on Twitter : @mondecanews <http://twitter.com/#%21/mondecanews>
----------------------------------------------------------
Received on Monday, 2 June 2014 13:23:17 UTC

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