Re: UCR issue 26

2015-10-14 14:54 GMT+02:00 Bill Roberts <bill@swirrl.com>:

> Hi all
>
> Sorry to perhaps re-open a much older discussion - but while I appreciate
> the importance of specifying temporal aspects of spatial data, tackling the
> fundamentals of 'temporal data on the web' feels like it ought to be beyond
> our scope.  Is no-one else addressing this under the general Data on the
> Web umbrella?  We need it, and if no other group has solved it then I
> suppose we have to - but it feels like something that has much broader
> applicability than in our working group.
>

We are discussing a requirement for the OWL Time deliverable
<http://www.w3.org/2015/spatial/charter#time>, one of the five deliverables
in the SDWWG charter. Because this deliverable is in the charter, by
definition it is in scope for our working group. But I admit I have
wondered how the OWL Time deliverable came to be in scope for the Spatial
Data on the Web Working Group. I can think of a few reasons, but to me
there is not a clear natural association.

Regards,
Frans



> Cheers
>
> Bill
>
> On 14 October 2015 at 06:25, Alejandro Llaves <allaves@fi.upm.es> wrote:
>
>> Hi Frans,
>>
>> IMO, the two examples included in the current description of the
>> vagueness requirement are fair examples of vague and imprecise temporal
>> descriptions (added after a group's discussion, if I remember correctly).
>> As Rachel said, "afternoon of June 1st" may have different interpretations
>> on the ending time, not to mention that the year is missing. In the case of
>> "second quarter of the 9th century", there is no reference to the calendar
>> used; and depending on the event granularity, e.g. an earthquake or a war,
>> 25 years may be more or less imprecise.
>>
>> Cheers,
>> Alejandro
>>
>> On 9 October 2015 at 17:52, Heaven, Rachel E. <reh@bgs.ac.uk> wrote:
>>
>>> The vagueness (e.g. “before 1972” or “early 1950s”, or even “the end of
>>> the Jurassic”) can usually be expressed by an interval with a different
>>> precision on each end, or an undefined start or end.  “Afternoon of June
>>> 1st” is an interval with a precise start time and a less precise end,
>>> depending on culture and season...
>>>
>>>
>>>
>>> Then there are the other examples where one component of the date might
>>> be known very precisely (a photo from Christmas day), but the year is known
>>> with less certainty.
>>>
>>>
>>>
>>> So perhaps:
>>>
>>> 'It should be possible to make use of possibilities of temporal
>>> reference systems to express components of time instants and components of
>>> time intervals at various levels of precision'.
>>>
>>>
>>>
>>> Regards,
>>>
>>> Rachel
>>>
>>>
>>>
>>> *From:* Frans Knibbe [mailto:frans.knibbe@geodan.nl]
>>> *Sent:* 09 October 2015 14:25
>>> *To:* Jon Blower
>>> *Cc:* SDW WG Public List
>>> *Subject:* Re: UCR issue 26
>>>
>>>
>>>
>>> Hi Jon,
>>>
>>>
>>>
>>> Yes, I think this is about temporal precision. For Gregorian time it is
>>> possible to have different precisions in ISO 8601: 2003-04-27T23:45 is more
>>> precise than 2003-04-27, which is more precise than 2003. I don't think
>>> playing with precision like this is possible with XSD datatypes, especially
>>> when one is limited to xsd:dateTime.
>>>
>>>
>>>
>>> Other temporal reference systems have precision too. For example, in
>>> geological time 'Paleogene' is more precize than 'Cenozoic'.
>>>
>>>
>>>
>>> That would bring me to a requirement like 'It should be possible to make
>>> use of possiblities of temporal reference systems to express time at
>>> various levels of precision'.
>>>
>>>
>>>
>>> Regards,
>>>
>>> Frans
>>>
>>>
>>>
>>> 2015-10-08 17:38 GMT+02:00 Jon Blower <j.d.blower@reading.ac.uk>:
>>>
>>> Hi Frans,
>>>
>>>
>>>
>>> I see your point (both examples could be seen as extremely precise,
>>> depending on our expectations and application).
>>>
>>>
>>>
>>> Maybe instead of calling the requirement “temporal vagueness” it should
>>> be “temporal precision”, the requirement being to be able to express the
>>> precision of a time value.
>>>
>>>
>>>
>>> Cheers,
>>>
>>> Jon
>>>
>>>
>>>
>>> On 8 Oct 2015, at 15:59, Frans Knibbe <frans.knibbe@geodan.nl> wrote:
>>>
>>>
>>>
>>> Hello,
>>>
>>>
>>>
>>> This is a thread for trying to resolve UCR issue 26
>>> <https://www.w3.org/2015/spatial/track/issues/26>. Again, the issue
>>> deals with clarification of a requirement. In this case it is about the OWL
>>> Time requirement Temporal vagueness
>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#TemporalVagueness>
>>> .
>>>
>>>
>>>
>>> Current phrasing is: *"It should be possible to describe time points
>>> and intervals in a vague, imprecise manner. For instance, to represent an
>>> event happened on the afternoon of June 1st or at the second quarter of the
>>> 9th century."*
>>>
>>>
>>>
>>> The examples seem to be neither vague nor imprecise. Could other
>>> examples be supplied, or could be explained why the examples are vague
>>> and/or imprecise?
>>>
>>>
>>>
>>> Especially the time specialists among us: please help in getting this
>>> requirement in shape.
>>>
>>>
>>>
>>> Greetings,
>>>
>>> Frans
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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>>>
>>> --
>>> Alejandro Llaves
>>>
>>> Ontology Engineering Group (OEG)
>>>
>>> Artificial Intelligence Department
>>>
>>> Universidad Politécnica de Madrid
>>>
>>> Avda. Montepríncipe s/n
>>>
>>> Boadilla del Monte, 28660 Madrid, Spain
>>>
>>>
>>> http://www.oeg-upm.net/index.php/phd/325-allaves
>>>
>>>
>>> allaves@fi.upm.es
>>>
>>>
>