Re: Encoding an incomplete date as xsd:dateTime

I don't think you want to go down the road of comparing MARC and the
semantic web.  Young librarians resent all the numeric codes,  but
people walk into libraries all over the world and use MARC records and
never even know they are doing it.  The designers of MARC made good
decisions that have kept the oldest standard format with variable
length fields going strong.

You're free to publish whatever vocabulary you want and that's why the
person who wants to merge the mess you published with somebody else's
mess needs to have "one ring to rule them all" somewhere in their
system.  They might not even want to use it all the time,  but as the
scale of what you ingest grows,  you need to be able to tie a bow on
to a solution for this one and move on.

I think what's great about RDF and SPARQL is that there is a clear
path as to how to add new data types and functions on those types,  so
figuring out the algebra of EDTF and making it available as SPARQL
functions ought to be doable.


ᐧ

On Wed, Jun 25, 2014 at 10:42 AM, Jerven Bolleman <me@jerven.eu> wrote:
> Hi Bernard,
>
> Please do not go down the stuff everything in a single literal format
> that EDTF is. That is not a semweb solution that is a MARC solution.
> If that level of detail is really needed modeling it using the
> TimeOntology plus extra information for seasons etc.. is the correct
> way to go.
>
> Problems for EDTF is that OWL reasoners don't understand it. You can't
> SPARQL with it. And in general is just not appropriate in actually
> describing the time ranges.
> In other words I do not think this is appropriate for a standard
> ontology like vCard.
>
> Regards,
> Jerven
>
> On Wed, Jun 25, 2014 at 4:26 PM, Bernard Vatant
> <bernard.vatant@mondeca.com> wrote:
>> Hi all
>>
>> Are you aware of the Library of Congress Extended Date/Time Format (EDTF)?
>> There was an interesting presentation at DC 2013 about its implementation in
>> real world
>> http://dcevents.dublincore.org/IntConf/dc-2013/paper/view/183
>>
>> Bernard
>>
>>
>> 2014-06-25 16:00 GMT+02:00 Paul Houle <ontology2@gmail.com>:
>>
>>> I've been thinking about date representations a lot lately.  Even if
>>> you're going to cobble something together out of the various XSD
>>> types,  it still helps to have a theory.
>>>
>>> A better underlying data type for dates is a time interval or set of
>>> time intervals.
>>>
>>> This represents the fact that many "events" happen over a time
>>> interval (such as a meeting or movie show time),  that we often only
>>> know a year or a day,  that things are measured on idiosyncratic time
>>> basis such as the fiscal years of various organizations,  that there
>>> are both practical and theoretical limits on both the precision and
>>> accuracy of time measurements.
>>>
>>> Intervals have their charms,  but if you include interval sets you can
>>> also represent concepts such as "Monday", "June 25" and "the third
>>> Tuesday of the month".
>>>
>>> Of course,  it creates trouble that there is no total ordering over
>>> intervals/interval sets,  but that's a fundamental problem to any
>>> flexible time representation.
>>> ᐧ
>>>
>>> On Mon, Feb 10, 2014 at 9:37 AM, Heiko Paulheim
>>> <heiko@informatik.uni-mannheim.de> wrote:
>>> > Hi all,
>>> >
>>> > xsd:dateTime and xsd:date are used frequently for encoding dates in RDF,
>>> > e.g., for birthdays in the vcard ontology [1]. Is there any best
>>> > practice to
>>> > encode incomplete date information, e.g., if only the birth *year* of a
>>> > person is known?
>>> >
>>> > As far as I can see, the XSD spec enforces the provision of all date
>>> > components [2], but "1997-01-01" seems like a semantically wrong way of
>>> > expressing that someone is born in 1997, but the author does not know
>>> > exactly when.
>>> >
>>> > Thanks,
>>> > Heiko
>>> >
>>> > [1] http://www.w3.org/2006/vcard/ns
>>> > [2] http://www.w3.org/TR/xmlschema-2/#dateTime
>>> > [3] http://www.w3.org/TR/xmlschema-2/#date
>>> >
>>> > --
>>> > Dr. Heiko Paulheim
>>> > Research Group Data and Web Science
>>> > University of Mannheim
>>> > Phone: +49 621 181 2646
>>> > B6, 26, Room C1.08
>>> > D-68159 Mannheim
>>> >
>>> > Mail: heiko@informatik.uni-mannheim.de
>>> > Web: www.heikopaulheim.com
>>> >
>>> >
>>>
>>>
>>>
>>> --
>>> Paul Houle
>>> Expert on Freebase, DBpedia, Hadoop and RDF
>>> (607) 539 6254    paul.houle on Skype   ontology2@gmail.com
>>>
>>
>>
>>
>> --
>> 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
>> ----------------------------------------------------------
>
>
>
> --
> Jerven Bolleman
> me@jerven.eu



-- 
Paul Houle
Expert on Freebase, DBpedia, Hadoop and RDF
(607) 539 6254    paul.houle on Skype   ontology2@gmail.com

Received on Wednesday, 25 June 2014 15:17:07 UTC