Re: The 'valid time' requirement

Hello all,

Following the vote in yesterday's meeting I have closed ISSUE-16 and
changed the text of the valid time requirement
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#ValidTime>.
I have added a note that hopefully clarifies the requirement and does
justice to concerns that have been expressed.

Regards,
Frans

2015-10-27 0:00 GMT+01:00 Svensson, Lars <L.Svensson@dnb.de>:

> Frans,
>
> On Monday, October 26, 2015 3:26 PM, Frans Knibbe wrote:
>
> > 2015-10-22 20:09 GMT+02:00 Svensson, Lars <L.Svensson@dnb.de>:
> > Frans,
> > [...]
> > >
> > > The community behind the DCMI metadata terms could also be a good
> > > target. It has the definition of dcterms:valid, which can be used to
> indicate
> > > the temporal validity of data. Unfortunately, it is restricted to
> dates. What
> > we
> > > probably want is make use of other expressions of time to indicate the
> > > interval in which something is valid, and to be able to use temporal
> > functions
> > > (Allen's algebra) on validity intervals. So once OWL Time gets updated
> to
> > > allow more freedom in expressions of time, it would be great if the
> DCMI
> > had
> > > a 'valid' property with a liberal time range, for which OWL Time based
> > > expressions can be used.
> > dcterms:valid isn't necessarily restricted to dates. The property has
> range
> > rdf:Literal and refines dcterms:date [1]. The range of dcterms:date is
> also
> > rdf:Literal (surprise...), its definition is "a point or period of time
> associated
> > with an event in the lifecycle of the resource" (period is good!) and the
> > comment says that "date may be used to express temporal information at
> > any level of granularity. Recommended best practice is to use an encoding
> > scheme, such as the W3CDTF profile of ISO 8601 [W3CDTF]", the important
> > part being "temporal information at any level of granularity".
> >
> > [1] http://purl.org/dc/terms/date
> >
> > Best,
> >
> > Lars
> >
> > Thank you for pointing this out. The repeated use of the word 'date'
> seems
> > to have misguided me. So actually it is allowed to use any
> representation of
> > intervals or instants of time, as long as it is a literal. That gives us
> more liberty
> > to use time representations from OWL Time.
> >
> > I wonder now... could the rdf:Literal range be too restrictive? I can
> imagine
> > well known time intervals like 'the Jurassic' to be resources instead of
> literals.
> > Just like http://dbpedia.org/resource/1995, an expression of a time
> interval
> > that is not a literal. Could OWL Time be made to work with temporal
> > reference systems that define such resources?
>
> I guess that we could create an appropriate sdwwg:valid that takes a
> time:Interval as its object. I'm not deep enough into OWL to know if we can
> make sdwwg:valid a sub-property of dcterms:valid but I guess that Antoine
> can answer that from the top of his head.
>
> Best,
>
> Lars
>