Re: Best Practice sub-team call: 14:00 UTC, 20-April-2016

Thanks Josh- good input to the discussion. I note your suggestion of
"adopting the GeoSPARQL ontology as a best first start [...]"

On Wed, 20 Apr 2016 at 13:53 Joshua Lieberman <jlieberman@tumblingwalls.com>
wrote:

> Regrets over having a conflict for today’s call. It will be useful to
> define what is meant or covered by “spatial ontology”. A notion of things
> that might mean is covered here:
> http://www.w3.org/2005/Incubator/geo/XGR-geo-ont-20071023/
>
> ISO 19107 covers geometries and operators, but the feature model as
> presented in 19109 is perhaps more relevant to the semantic question
> whether features are relevant on the Web. My sense is that feature
> discernment is relevant everywhere but there is resistance to the
> “complexity” of being explicit about it in Web content.
>
> The biggest hurdle may still be the divide between coordinate sequences as
> literals and coordinates as individual objects. Amazingly, that colors
> almost every aspect of debates over spatial ontologies, such as whether
> single latitude and longitude properties are enough  for anything
> worthwhile on the web.
>
> Lastly, “webbiness” is good, but so is geometric and geodetic validity and
> consistency. The BP group should consider adopting the GeoSPARQL ontology
> as a best first start and charging OGC with developing a normative update
> to that. Everyone likes to make their own ontology, but the compatibility
> and computability issues then make for problems in large-scale spatial data
> representations.
>
> —Josh
>
>
> Joshua Lieberman, Ph.D.
> Principal
> Tumbling Walls
> jlieberman*tumblingwalls.com
> +1 617 431 6431
>
> On Apr 20, 2016, at 5:53 AM, Frans Knibbe <frans.knibbe@geodan.nl> wrote:
>
> Hello Jeremy,
>
> Thank you for acknowledging the issue. Yes, I can try to introduce the
> problem in the meeting. If we decide we could try working towards the
> spatial ontology there are still a lot of ways in which we could do that.
> To start with
>
> the mathematical foundations was just a suggestion. Another step could be
> to take a good look at ISO 19107 abstract model and see how that fits web
> requirements and see if it is possible to make that model available as web
> semantics, to be used as a foundation for other web models involving
> spatial data.
>
> Regards,
> Frans
>
>
>
> 2016-04-19 23:28 GMT+02:00 Jeremy Tandy <jeremy.tandy@gmail.com>:
>
>> Frans - thanks for the suggestion. Simon, Andrea - thanks for discussion.
>> Certainly a thorny issue to resolve, but one that we need to address openly
>> and transparently. Even if a single solution cannot be found, we _will_
>> need to document the reasons why a single solution is not possible - which
>> will help us establish [best] practices for when and where each of the
>> multiple solutions should be used. Of course, life would be easier with one
>> solution; so we should begin by striving for that.
>>
>> If we're going to start from mathematical foundations, this sounds like a
>> rigorous piece of work. Would it be best published as an independent Note?
>> (the WG has the remit to do so if we see fit).
>>
>> I've updated the agenda [1] to include the proposed topic (see below).
>> Frans - can you take the lead on this subject please? Given that this is a
>> massive topic, we won't finish the discussion in one meeting! So I will
>> time-box the discussion to 30-mins to allow for time to discuss other items.
>>
>> *Part 1 (30-mins): establishing an "agreed spatial ontology"*
>>
>>    - *[Frans] problem statement*
>>    - *solution criteria - what do we need the "agreed spatial ontology"
>>    to do?*
>>    - *prior art - what can we learn from (and where are the overlaps and
>>    gaps in existing work)*
>>    - *define plan of work - how do we move forward; who will lead?*
>>
>>
>> [1]:
>> https://www.w3.org/2015/spatial/wiki/Meetings:BP-Telecon20160420#Main_agenda
>>
>> On Tue, 19 Apr 2016 at 11:57 Frans Knibbe <frans.knibbe@geodan.nl> wrote:
>>
>>> Yes, it would be tough issue. But I am afraid that not addressing the
>>> issue properly will incur much greater costs. Perhaps not on our group, but
>>> certainly on society and the web as a whole. But also within our group
>>> there can be immediate benefits of having a basic spatial ontology. I have
>>> the feeling that many of the problems we are trying to solve are are a
>>> result of the absence of a solid theoretical foundation of the things we
>>> try to work with. We are mostly scratching the surface instead of attacking
>>> the core issues. I think it is likely that if the few core issues are
>>> resolved satisfactorily, many other problems will cease to be problems.
>>>
>>> I also think that the undertaking of defining a spatial ontology can be
>>> broken up in consecutive steps. We do not need to finish all those steps in
>>> order to be successful. But we can leave a solid foundation for others
>>> to continue with.
>>>
>>> To keep things simple, a first goal could be just to define vector
>>> geometry as a data type. Having just that would solve a lot of
>>> interoperability problems and would clear the way for universal ways of
>>> storing and exchanging spatial data. Humanity has been able to do the same
>>> for numbers and text, and having agreed upon models for those data types
>>> makes IT a lot simpler than it would have been if there was no such
>>> agreement.
>>>
>>> So a first step could be defining vector geometry as a mathematical
>>> construct, an ordered set of coordinates in some reference system. Much
>>> could be built on top of such a foundation, and even if in the end there
>>> would still be need for different serializations of geometry, it would help
>>> if those serializations share a common base model - going to a more basic
>>> level would achieve interoperability. And if the mathematical foundations
>>> are solid, a lot of derived ways of working with spatial data
>>> (transformations, spatial relationships, topology,...) will be much easier
>>> to set up. And as said before, we would also have a common ground for
>>> geographic geometry and non-geographic geometry, so that we can use methods
>>> from both worlds interchangeably.
>>>
>>> Perhaps what has been going on in the area of improving temporal data
>>> on the web can be an example for spatial data. I noticed that when a
>>> mathematical approach to time is adopted, the difference between time
>>> instants and time intervals disappears. On the surface there still is a
>>> difference, but at the core the situation is simpler. At the core, the
>>> concept of time is more unified than all the different expressions that can
>>> be encountered in the wild. I think that the same principle - going to the
>>> core of the matter to make things simpler and more universal - can also be
>>> applied to spatial data.
>>>
>>> Regards,
>>> Frans
>>>
>>>
>>>
>>> 2016-04-19 1:36 GMT+02:00 <Simon.Cox@csiro.au>:
>>>
>>>> +1 for considering this openly.
>>>>
>>>> It is probably the issue that the wider community would most expect to
>>>> see dealt with in the WG. However, it is definitely a tough issue, and I’m
>>>> sceptical that it is possible or even desirable to imagine that a single
>>>> solution is necessary.
>>>>
>>>>
>>>>
>>>> *From:* Frans Knibbe [mailto:frans.knibbe@geodan.nl]
>>>> *Sent:* Monday, 18 April 2016 11:42 PM
>>>> *To:* Jeremy Tandy <jeremy.tandy@gmail.com>
>>>> *Cc:* SDW WG Public List <public-sdw-wg@w3.org>
>>>> *Subject:* Re: Best Practice sub-team call: 14:00 UTC, 20-April-2016
>>>>
>>>>
>>>>
>>>> Hello Jeremy,
>>>>
>>>>
>>>>
>>>> Could this meeting be an opportunity to discuss the 'agreed spatial
>>>> ontology' mentioned in the charter (also see this e-mail thread
>>>> <https://lists.w3.org/Archives/Public/public-sdw-wg/2016Mar/0057.html>)?
>>>> I feel it could be the most crucial contribution to the data web our group
>>>> could make, so it would be good to have more clarity on whether and how we
>>>> wish to pursue this.
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>> Frans
>>>>
>>>>
>>>>
>>>> 2016-04-18 12:09 GMT+02:00 Jeremy Tandy <jeremy.tandy@gmail.com>:
>>>>
>>>> All. For those participating in the Best Practices sub-team, the next
>>>> meeting is scheduled for 14:00 UTC this Wednesday (20-April).
>>>>
>>>>
>>>>
>>>> Preliminary agenda is here:
>>>> https://www.w3.org/2015/spatial/wiki/Meetings:BP-Telecon20160420
>>>>
>>>>
>>>>
>>>> Please advise if you want to add anything. If you can't make the
>>>> meeting, please record your 'regrets', else we'll see you there.
>>>>
>>>>
>>>>
>>>> Regards - Jeremy, Linda and Payam.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>
>