- From: Rob Atkinson <rob@metalinkage.com.au>
- Date: Fri, 19 Aug 2016 02:10:00 +0000
- To: Rob Atkinson <rob@metalinkage.com.au>, Frans Knibbe <frans.knibbe@geodan.nl>
- Cc: Joshua Lieberman <jlieberman@tumblingwalls.com>, Jeremy Tandy <jeremy.tandy@gmail.com>, Linda van den Brink <l.vandenbrink@geonovum.nl>, SDW WG Public List <public-sdw-wg@w3.org>, Payam Barnaghi <payam.barnaghi@gmail.com>
- Message-ID: <CACfF9Ly1zWL_xjNm9Aj=VBD2_Kxk8pD2j2QX4DmLZ30vn3TxOQ@mail.gmail.com>
while I'm looking over the requirements document, I notice that there are quite a lot of requirements about observations and coverages, such as "5.30 Observed property in coverage" but no explicit mention of a requirement to state the units of measure. Perhaps simply update 5.30 to include this? Likewise, the only mention of precision is in the cultural heritage use case - i would have thought there was a requirement to be able to state the spatial and temporal precision of values. In many ways this one of the defining requirement for making spatial "special" in terms of a BP ;-) Cheers Rob On Fri, 19 Aug 2016 at 11:58 Rob Atkinson <rob@metalinkage.com.au> wrote: > Mainly it was looking ahead :-) But IMHO it is important to get the > intent, then wording, of such requirements right - is it for there to be > guidance for how a community might solve such a problem, or is it for > interoperability in the broader ecosystem of tools - i.e. the community is > the virtual community of W3C or OGC standards implementers. > > GeoSPARQL is the latter case, > CRS definitions is the former - but one where the OGC makes > recommendations and uses specific CRS definitions as defaults in some > specifications. > > The key thing for this requirement is whether vague descriptions are > a) purely textual annotations (in which case we probably dont need to say > anything about them at all in the BP) > b) qualifications for a geometry property (in which case we probably want > to define a vocabulary to identify such properties, and how to bind these > to multiple geometries in a single feature - perhaps annotations need to > apply to all provided geometries) > c) machine-readable constructs (possibly with qualifications) - i.e. the > ability to say A isNear B > > I would suggest its necessary for a BP to handle machine readable location > descriptions with human readable annotations, i.e. cases b,c where A > relatedTo B and either A or B is a spatialThing. Note this covers > providing a note about geometry per feature. > > Thus, I'd be tempted to say - in the BP - if the relationship can be > expressed using the GeoSPARQL specification, then this should be used, > either directly or by specialisation to introduce domain specific semantics > domain-independent spatial operation. Otherwise follow the general BP > regarding vocabulary re-use. > > In, for example hydrology, a description of where a stream gauge is > located relative to a stream confluence is actually far more precise than a > coordinate somewhere near the confluence - which may be upstream, > downstream or at the actual confluence in fact. > > In the Requirements, therefore, I'd be tempted to rephrase > "vague,imprecise" to "non-coordinate based" - and then identify the above > cases and state which is in scope. > > > Rob > > > On Thu, 18 Aug 2016 at 20:37 Frans Knibbe <frans.knibbe@geodan.nl> wrote: > >> Hello Rob, >> >> Was your comment intended as criticism of the proposed rephrasing of the >> spatial vagueness requirement? Or is it only looking ahead to possibilities >> of meeting such a requirement? >> >> Although the primary concern of this thread is to formulate the right >> requirement(s), I must admit in this particular case it is interesting to >> think of possible ways of making it possible. >> >> Again I think a spatial ontology could be really helpful. Let's take some >> examples of text that might be turned into spatial data: >> >> 1. The Carthaginian army was defeated near the southwest border of >> the Roman empire. >> 2. The suspect moved from the entrance of the bank to a red car that >> was parked near the post box. >> >> The first example might come from a historical source and the second >> could be an example of crowd sourced data, two use cases in which vague >> spatial data are typically encountered. >> >> A hypothetical spatial ontology will have definitions of the concepts of >> 'spatial thing' and 'spatial relationship'. So at least we could flag the >> locations and the spatial relationships in these statements as such. That >> could already be helpful. >> >> Now in the first example it is imaginable that a resource exists that >> defines the terms used in a domain context. Historians studying the Roman >> empire could make a vocabulary in which the general classes for location >> and spatial relationships are specialised. It could have a collection of >> linestrings marking the borders of the empire through time, and it could >> have a definition of the spatial relationship 'near', which in historical >> Roman texts could always mean 'a distance of at most one day's marching'. >> Furthermore, the spot where the battle took place could be represented >> as a 2D point geometry with unknown coordinates (by the way, a possible >> example of why the coordinates should not be a mandatory part of a >> geometry). >> >> For crowd sourced information, definitions of vague terms that are used >> will probably be more difficult to outsource to domain vocabularies. >> Definitions of terms can be as diverse as the crowds using the terms. But >> at least flagging the locations and spatial relationships using the general >> spatial ontology could be useful. >> >> Regards, >> Frans >> >> On 18 August 2016 at 01:10, Rob Atkinson <rob@metalinkage.com.au> wrote: >> >>> IMHO this is covered by the general vocabulary re-use clause - such >>> vague terms are domain specific semantics - therefore in general you should >>> look to re-use a set of relationship properties, as defined in an ontology, >>> published by the community of practice you intend your data to be >>> understood by/interoperable with. >>> >>> In general, one should look first to the OGC for spatial concerns, to >>> see if such a community has either published what you need, or has a >>> governance structure in place (a Domain Working Group) where such a >>> vocabulary can be shared. (note that OGC will reference relevant >>> vocabularies published by other SDOs.... so its a sensible starting point >>> IMHO) >>> >>> Rob >>> >>> On Wed, 17 Aug 2016 at 23:10 Joshua Lieberman < >>> jlieberman@tumblingwalls.com> wrote: >>> >>>> Can we distinguish between qualitative relationships such "bottom of >>>> the hillside” which are as precise as the features being referenced, and >>>> fuzzy ones such as “near the hillside” that explicitly use imprecise >>>> relationships? >>>> >>>> Josh >>>> >>>> On Aug 17, 2016, at 9:00 AM, Frans Knibbe <frans.knibbe@geodan.nl> >>>> wrote: >>>> >>>> Dear group members, especially the BP editors, >>>> >>>> It would be great if we can resolve this sleeping issue >>>> <https://www.w3.org/2015/spatial/track/issues/30> before the next PWD >>>> of the UC&R document. To summarise the issue, it seems clear what the >>>> requirement is: there is a need to be able to use vague/informal/colloquial >>>> expressions to refer to either spatial things or spatial relationships. >>>> >>>> I still think the easiest solution is to change the existing Spatial >>>> vagueness >>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialVagueness> >>>> requirement a bit. The core requirement would then be something like "It >>>> should be possible to use vague or informal expressions to indicate >>>> locations or spatial relationships". That requirement could be followed by >>>> some examples: >>>> >>>> for locations: >>>> >>>> - at the bottom of the hillside >>>> - downtown Los Angeles >>>> - London (has multiple definitions, so just the name is not precise) >>>> - the south west boundary of the Roman Empire >>>> >>>> for spatial relationships: >>>> >>>> - near >>>> - across the street from >>>> - upstairs >>>> - at walking distance from >>>> >>>> What do you think? >>>> >>>> Regards, >>>> Frans >>>> >>>> On 20 October 2015 at 14:04, Frans Knibbe <frans.knibbe@geodan.nl> >>>> wrote: >>>> >>>>> >>>>> >>>>> 2015-10-16 11:15 GMT+02:00 Jeremy Tandy <jeremy.tandy@gmail.com>: >>>>> >>>>>> Hi Frans- >>>>>> >>>>>> I'm not sure that your option (1) covers the terms used for 'vague' >>>>>> (or, more accurately, _relative_) spatial relationships. I think that we >>>>>> might want to refer to the location of a post box unambiguously, based on >>>>>> it's position within a topological (road) network; e.g. 150 from the >>>>>> junction of roads A and B in the direction of [etc.] ... the junction (a >>>>>> node in the network) might have a geometric position (e.g. collected by a >>>>>> surveyor with GPS), but the position of street furniture may be recorded >>>>>> using relative positions. >>>>>> >>>>> >>>>> We already have a requirement for being able to use spatial >>>>> relationships, see the Spatial relationships requirement >>>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialRelationships>. >>>>> If that requirement is met, it should be possible to express the location >>>>> of a post box relative to some topographic or topological point, wouldn't >>>>> you say? >>>>> >>>>> However, the ability to be vague about relative positioning does not >>>>> seem to have been addressed yet. One might want to say that a post box is >>>>> close to the butcher shop, or over the road from the bakery. >>>>> >>>>> Regards, >>>>> Frans >>>>> >>>>> >>>>>> >>>>>> Does that help? >>>>>> >>>>>> Jeremy >>>>>> >>>>>> On Wed, 14 Oct 2015 at 13:17 Frans Knibbe <frans.knibbe@geodan.nl> >>>>>> wrote: >>>>>> >>>>>>> Rachel and Jeremy, thank you for helping us solve this case. >>>>>>> >>>>>>> So this is about being able to use colloquial terms for both >>>>>>> location and spatial relationships. It seems to me that the first >>>>>>> part, colloquial terms for location is basically covered by the Spatial >>>>>>> vagueness requirement >>>>>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialVagueness>. >>>>>>> Interestingly enough, this requirement has not been related to the Best >>>>>>> Practices requirement. >>>>>>> >>>>>>> What we could do is: >>>>>>> >>>>>>> 1. Rephrase the spatial vagueness requirement a bit to make it >>>>>>> clearly cover examples like “the midlands”, “town centre”, how different >>>>>>> people define “London”. >>>>>>> 2. Relate the spatial vagueness requirement to the Locating a >>>>>>> Thing use case >>>>>>> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#LocatingAThing> >>>>>>> and the Best Practices deliverable >>>>>>> >>>>>>> For the requirement to be able to use colloquial terms for spatial >>>>>>> relationships we could either expand the definition of the Spatial >>>>>>> vagueness requirement, or add a new requirement, so that we end up with >>>>>>> separate requirements for spatial vagueness for locations and spatial >>>>>>> vagueness for relationships. I would favour the first option, to keep >>>>>>> things simple, and because there is of plenty of overlap between the >>>>>>> requirements. >>>>>>> >>>>>>> Regards, >>>>>>> Frans >>>>>>> >>>>>>> >>>>>>> 2015-10-13 18:03 GMT+02:00 Jeremy Tandy <jeremy.tandy@gmail.com>: >>>>>>> >>>>>>>> Hi- >>>>>>>> >>>>>>>> Rachel is correct; 'Locating a thing' [1] (provided by @eparsons) >>>>>>>> is the source of this requirement. The description provided in her message >>>>>>>> is accurate. Ed also uses phrases like "upstairs", "where I left it" etc. >>>>>>>> >>>>>>>> It's not about geocoding; it's about relating position in human >>>>>>>> terms ... all about context. >>>>>>>> >>>>>>>> FWIW, there are already some reasonable models from OGC about >>>>>>>> describing relative positioning - usually related to position within a >>>>>>>> topological network offset from a node in that network (e.g. position of >>>>>>>> signage on a railway, position of a lamp post on a street etc.) >>>>>>>> >>>>>>>> Jeremy >>>>>>>> >>>>>>>> [1]: >>>>>>>> http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#LocatingAThing >>>>>>>> >>>>>>>> >>>>>>>> On Fri, 9 Oct 2015 at 17:37 Heaven, Rachel E. <reh@bgs.ac.uk> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Hi Frans >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Looks like this is from the “Locating a thing” use case, >>>>>>>>> >>>>>>>>> >>>>>>>>> https://www.w3.org/2015/spatial/wiki/Working_Use_Cases#Locating_a_thing >>>>>>>>> ... >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> It’s about vernacular geography : human terms for relative >>>>>>>>> spatial positioning (“upstairs”, “over the road from”) and human concepts >>>>>>>>> of places (“the midlands”, “town centre”, how different people define >>>>>>>>> “London”). These extents are usually vague and do not match official >>>>>>>>> authoritative boundaries, so you can’t geocode them accurately, if at all. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> It will also be very relevant to harvesting crowd sourced data >>>>>>>>> https://www.w3.org/2015/spatial/wiki/Working_Use_Cases#Crowd_sourced_earthquake_observation_information_.28Best_Practice.2CSSN.29 >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Cheers, >>>>>>>>> >>>>>>>>> Rachel >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> *From:* Frans Knibbe [mailto:frans.knibbe@geodan.nl] >>>>>>>>> *Sent:* 09 October 2015 14:11 >>>>>>>>> *To:* SDW WG Public List; Kerry Taylor; Jeremy Tandy >>>>>>>>> *Subject:* UCR issue 30: missing requirement >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Hello. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> This is the thread for discussion of UCR issue 30 >>>>>>>>> <http://www.w3.org/2015/spatial/track/issues/30>, the Case of the >>>>>>>>> Mysterious Missing Requirement. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> The current description reads: '*see " relative (spatial) >>>>>>>>> relationships based on context e.g. my location [expressing location and >>>>>>>>> places in human terms] " from * >>>>>>>>> >>>>>>>>> *https://www.w3.org/2015/spatial/wiki/BP_Consolidated_Narratives#linking_data >>>>>>>>> <https://www.w3.org/2015/spatial/wiki/BP_Consolidated_Narratives#linking_data>'. Jeremy >>>>>>>>> might know what use case it came from.'* >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> To me is not exactly clear yet what the requirement could be. >>>>>>>>> Resolving location names in human terms to geometry is called geocoding and >>>>>>>>> is a well established practice. Could this be about the need for having >>>>>>>>> human language equivalents for spatial relations? I can see that would be a >>>>>>>>> benefit for finding spatial data using a search engine. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> If we find the related use case(s) we will probably get a better >>>>>>>>> idea of what the missing requirement could look like, >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Regards, >>>>>>>>> >>>>>>>>> Frans >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> ------------------------------ >>>>>>>>> This message (and any attachments) is for the recipient only. NERC >>>>>>>>> is subject to the Freedom of Information Act 2000 and the contents of this >>>>>>>>> email and any reply you make may be disclosed by NERC unless it is exempt >>>>>>>>> from release under the Act. Any material supplied to NERC may be stored in >>>>>>>>> an electronic records management system. >>>>>>>>> ------------------------------ >>>>>>>>> >>>>>>>> >>>>>>> >>>>> >>>> >>>> >>
Received on Friday, 19 August 2016 02:10:56 UTC