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Re: Requirement for 'Valid Time' Issue-16

From: Frans Knibbe <frans.knibbe@geodan.nl>
Date: Wed, 11 Nov 2015 15:53:04 +0100
Message-ID: <CAFVDz40H80rnspDAvnN5KSgKcMnS0eS50M-Uq_ePn7TjKRE80A@mail.gmail.com>
To: "Little, Chris" <chris.little@metoffice.gov.uk>
Cc: "public-sdw-wg@w3.org" <public-sdw-wg@w3.org>, Simon Cox <Simon.Cox@csiro.au>, "Tandy, Jeremy" <jeremy.tandy@metoffice.gov.uk>, "Kerry Taylor (Kerry.Taylor@acm.org)" <Kerry.Taylor@acm.org>
Oops... accidentaly touched the Enter button and my message got sent
prematurely. Please ignore my previous message.

My comments are inline:


>
> 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)? The distinction is important in this
case.


> 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.
>>
> It is issues like these that would require an alignment effort. So that
problem could be addressed if we opt for the phrasing I proposed.

Also please note Lars's statements on this particular matter (here
<https://lists.w3.org/Archives/Public/public-sdw-wg/2015Oct/0198.html>).


Regards,
Frans



> 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
>>
>>
>>
>>
>
>
Received on Wednesday, 11 November 2015 14:53:34 UTC

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