Re: Requirement for 'Valid Time' Issue-16

2015-11-11 15:17 GMT+01:00 Little, Chris <chris.little@metoffice.gov.uk>:

> Frans, Kerry
>
>
>
> I now have Issue-16 in both the body and subject of the email for the
> tracker to spot it. Thanks Kerry.
>
>
>
> So is the debate between Kerry and Frans: “entirely in-scope for us to
> take a position”
>
In scope for which deliverable(s)?

> and "Ensure alignment with existing methods for expressing the time in
> which data are valid (e.g. http://purl.org/dc/terms/valid)."
>

The problem I have with Dublin Core as it stands is that it specifies “Date
> valid” and it is not clear whether this is inclusive of “Time” with hours
> minutes seconds etc.
>
> Chris
>
> *--------------------------------------------------*
>
> *From:* Kerry Taylor [mailto:Kerry.Taylor@acm.org]
> *Sent:* Tuesday, November 10, 2015 9:26 PM
> *To:* Little, Chris
> *Cc:* public-sdw-wg@w3.org; Frans Knibbe; Simon Cox; Tandy, Jeremy; Kerry
> Taylor (Kerry.Taylor@acm.org)
> *Subject:* Re: Requirement for 'Valid Time' issue-16
>
>
>
> I agree. I also heard a requirement of this form expressed by the wot
> interest  group in sapporo. We should either refer to the met ocean wg
> reference time, or build our own if that is not good enough.
>
> This is not strictly owl-time, but it is very near by and entirely
> in-scope for us to take a position.
>
>
>
> ( chris, mentioning ISSUE-16 in the email gets the message against  the
> issue in the tracker).
>
>
>
> Kerry
>
>
>
> *From:* Frans Knibbe [mailto:frans.knibbe@geodan.nl]
> *Sent:* Wednesday, November 11, 2015 1:42 PM
> *To:* public-sdw-wg@w3.org
> *Cc:* Simon Cox; Tandy, Jeremy; Kerry Taylor (Kerry.Taylor@acm.org);
> Little, Chris
> *Subject:* Re: Requirement for 'Valid Time'
>
>
>
> Thanks to Chris for continuing the discussion. My comments are inline:
>
>
>
> 2015-11-10 17:47 GMT+01:00 Little, Chris <chris.little@metoffice.gov.uk>:
>
> Dear colleagues,
>
> Unfortunately, tomorrow I will be travelling by train, with rubbish phone
> connections, so it will be highly unlikely that I can join in, so I will
> add my views on UCR-16 here:
>
> 1. I agree that 'Valid Time' is outside the scope of the Time OWL
> ontology, as are lots of other time semantics (verification time, time of
> last update, creation time, publication time, etc).
>
> 2. There are widely used ontologies that recognise different kinds of time
> e.g. Dublin Core.
>
> 3. It seems to be out of scope for spatial data as opposed to just 'data
> on the Web'. However, there are lots of examples in the spatial domain,
> such as environmental observational data and weather forecasts.
> Increasingly, to know a location, one needs to know when.
>
>
>
> True, but that by itself does not warrant us adopting this requirement.
> Examples of many aspects of handling data can be found in the spatial
> domain, but that does not mean we should consider working on them. Why make
> an exception for this particular example?
>
>
> 4. The Met Ocean Domain WG of OGC produced a Best Practice profile of the
> OGC WMS1.3 standard to capture some of these time concepts and improve
> interoperability arising from real world experience of interoperability
> problems. The BP gave a standard name for these non-standard time semantics
> ("Reference Time").
>
>
>
> As I see it, OGC semantics form a more or less closed system. Other than
> very basic data types they can not rely on semantics that are defined
> outside of the system. Hence the need to standardise aspects of reality
> that are not strictly spatial in the OGC. But since the SDWWG is acting in
> a web environment, it should be OK to have to rely on semantics that are
> defined somewhere out of our sphere of control.
>
>
> 5. I do not know if there is a generic 'framework' for capturing different
> time application level semantics in Data on the Web.
>
> 6. I think this is important for enough SDWWG Use Cases that it should not
> be ruled out of scope unless some other 'owner' is identified to take it
> forward.
>
>
>
> Yes, we could take it upon ourselves to make some other party the problem
> owner. But that would be something very different from taking it upon
> ourselves to work on semantics for valid time.
>
>
>
> This remark has led me to see the resemblance between ISSUE-16
> <https://www.w3.org/2015/spatial/track/issues/16> and ISSUE-11
> <https://www.w3.org/2015/spatial/track/issues/11>. There was a risk of
> having a requirement that would make us have to deal with the semantics of
> provenance. Now the provenance requirement
> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#Provenance> states
> that we should seek alignment of our work with existing standards for
> provenance. I believe that issue was resolved to everyone's satisfaction.
>
>
>
> In this case we could go the same way: have a requirement for OWL Time
> that says that the work should be aligned with existing methods of
> expressing valid time. That way we do acknowledge that valid time is
> important for spatial data, but we do not make it a primary responsibility
> for us to have semantics for valid time.
>
>
>
> This could lead to a requirement like:
>
>
>
> "Ensure alignment with existing methods for expressing the time in which
> data are valid (e.g. http://purl.org/dc/terms/valid)."
>
>
>
> In this case the appropriate related deliverable would be only OWL Time.
>
>
>
> Greetings,
>
> Frans
>
>
>
>
>
>
>
>
> HTH, Chris
>
>
> Chris Little
> Co-Chair, OGC Meteorology & Oceanography Domain Working Group
>
> IT Fellow - Operational Infrastructures
> Met Office  FitzRoy Road  Exeter  Devon  EX1 3PB  United Kingdom
> Tel: +44(0)1392 886278  Fax: +44(0)1392 885681  Mobile: +44(0)7753 880514
> E-mail: chris.little@metoffice.gov.uk  http://www.metoffice.gov.uk
>
> I am normally at work Tuesday, Wednesday and Thursday each week
>
>
>
>