13:59:27 RRSAgent has joined #sdwbp 13:59:27 logging to http://www.w3.org/2016/06/15-sdwbp-irc 13:59:29 RRSAgent, make logs world 13:59:29 Zakim has joined #sdwbp 13:59:31 Zakim, this will be SDW 13:59:31 ok, trackbot 13:59:32 Meeting: Spatial Data on the Web Working Group Teleconference 13:59:32 Date: 15 June 2016 13:59:56 present+ Linda 14:01:47 present+ frans 14:03:22 jtandy has joined #sdwbp 14:05:20 topic 14:05:37 present+ jtandy 14:06:24 regrets+ phila, kerry, eparsons, scottsimmons, bill, mattperry, clemens, josh, andrea, roba 14:06:37 regrets+ bart 14:06:49 scribe: Linda 14:07:32 jtandy: notes we don't have quorum so can't resolve anything 14:07:45 topic: patent call 14:07:56 14:08:21 agenda: https://www.w3.org/2015/spatial/wiki/Meetings:BP-Telecon20160615 14:08:44 jtandy: can we three have useful discussion on the topics that are on the agenda? 14:09:17 Frans: useful question. We could try to agree on something and present it to the larger group. 14:09:29 jtandy: ok 14:10:02 topic: Summarising email thread 14:10:03 topic: Summarising email thread about features, geometries and real world things 14:10:21 frans: the question is: what can we summarize and put in the BP 14:11:07 to quote Frans: Is there really a need to have a third concept (Feature)? If the world could manage with two core concepts, that would be preferable, wouldn't it? 14:11:34 so that leaves spatial things and geometry 14:12:43 frans: yes these two are enough, I think there was consensus about this. We should describe these two in the BP. 14:13:05 frans: definitions are missing 14:14:22 UML models for ISO TC 211 are free here: http://www.isotc211.org/hmmg/HTML/index.htm 14:14:33 page about further development of geosparql: https://www.w3.org/2015/spatial/wiki/Further_development_of_GeoSPARQL 14:16:26 jtandy: My conclusion is in the end nobody cares about the difference between the spatial things and the geometries. 14:16:46 frans: agrees, it's always about the digital models of things, not the real world things 14:18:35 jtandy: when people create linked data, and they want to record the color of a fire hydrant, they have the real world thing in their head. Fundamentally, people can figure it out. 14:18:53 An example: https://www.w3.org/TR/vocab-org/#org:Site 14:19:01 ... refers to TBLs VCard example. 14:19:41 * It is not uncommon for Spatial Data Infrastructures (SDI) to expose geographic datasets with overlapping scope. For example, two datasets may describe lighthouses in the UK: (i) maritime navigation aids, and (ii) aviation vertical obstructions. Both datasets may describe a Feature for Eddystone Lighthouse; each with attributes defined according to the relevant data model, e.g. one providing a point location and the light characteristic, the 14:19:41 other a detailed two-dimensional representation and obstruction height. Due to the constraints of SDIs, each Feature representing Eddystone Lighthouse would have a different unique identifier. One may assert that these two identifiers identify the same resource (e.g. using `owl:sameAs`). However, care needs to be taken when attempting such reconciliation as the concepts implied by the Feature Type use in each dataset may not be perfectly aligned. Do we 14:19:41 know that two Features are the same real-world Thing? Not really. Collocation of two Features is insufficient to determine ‘sameness’; we must also assess the semantics of each Feature Type and perhaps gather further supplementary evidence to determine if two Features are abstractions of the same real-world Thing. 14:20:06 ... I wrote the above in my notes. 14:23:06 frans: we can assume that people working with data on the web know that we are always talking about representations / models of things, not real world things themselves. 14:24:21 Linda: the Semmtech people have an issue that touches on this subject. 14:24:33 * The BBC defines their `core:sameAs` property to assert that “something is the same as something else, but in a way that is slightly weaker than owl:sameAs. It's purpose is to connect separate identities of the same thing, whilst keeping separation between the original statements of each.” Also note that schema.org [SCHEMA] defines a `sameAs` property that relates an entity to the URL of a reference Web page that provides unambiguous 14:24:33 identification of that entity; using `schema:sameAs` one could assert that both features were identified by [the information listed on] the same reference Web page. Similarly, one could use `isPrimaryTopicOf` [FOAF] 14:24:33 frans: is not the same thing 14:25:05 jtandy: BBC have created their own, weaker version of sameAs 14:25:08 https://www.w3.org/2015/spatial/track/issues/38 14:25:52 jtandy: let's get back to the constraints we have in SDIs. 14:27:27 ... a feature is an abstraction of a real world thing and is a member of one particular feature type. Is that the Semmtech issue? 14:27:55 frans: I'd have to look into it. 14:29:21 jtandy: Is the issue that there are different abstractions of the physical world and you want to somehow relate them? 14:29:28 Linda: that's how I understand it yes. 14:30:24 frans: they want to assert some kind of equivalence between two models of the same thing. This is missing. 14:31:07 frans: not only for spatial data but data in general. sameAs is too strong, seeAlso to weak. 14:31:34 jtandy: Could e.g. 'spatialSameAs' be part of the spatial ontology? 14:32:03 frans: perhaps, but it could also involve non-spatial models in practice. 14:32:21 jtandy: but could still be ok. Domain and range wouldn't need to be spatial objects. 14:32:45 would mean that both objects are talking about the same spatial object. 14:32:52 frans: could be a suggestion for spatial ontology work. 14:33:52 ... agreeing on the definition of this property could be hard. But we can put it on a to try list. 14:36:18 ... explanations of what is a spatial thing and what is a geometry belong in the BP. 14:36:30 propose: in the Best Practice document we talk about "spatial things" and "geometries" as being disjoint objects - and no-one cares about the incredibly subtle difference between "spatial things" and the term "Feature" as used in ISO/TC 211 and OGC ... so we will use the term "spatial thing" for simplicity 14:37:08 (topology is a special kind of spatial relationship) 14:38:41 (in the real world - with normal web developers - no one cares about the difference between spatial thing and Feature) 14:39:10 frans says that there are many definitions "floating around" ... but the Spatial Ontology should clarify this 14:39:15 frans: we should have an open description of what is meant by spatial things 14:39:46 Linda: like the description in basic geo 14:39:54 * SpatialThing: “Anything with spatial extent, i.e. size, shape, or position. e.g. people, places, bowling balls, as well as abstract areas like cubes.” [W3C Basic Geo] 14:40:10 * Feature: “A geographical feature, capable of holding spatial relations.” [NeoGeo] 14:40:15 * Location: “A spatial region or named place.” [DCTERMS] 14:40:39 "SpatialThing" is open enough for our needs. 14:40:44 +1 14:40:49 +1 14:40:56 +1 14:41:47 resolution: in the Best Practice document we talk about "spatial things" and "geometries" as being disjoint objects - and no-one cares about the incredibly subtle difference between "spatial things" and the term "Feature" as used in ISO/TC 211 and OGC ... so we will use the term "spatial thing" for simplicity 14:42:03 (at least given the 100% agreement from the three of us!) 14:42:35 jtandy: implication: the BP can remain simple, and the subtlety and definitions go in the spatial ontology. 14:42:49 frans: BP doc _needs_ to remain simple! 14:43:37 propose: we will use the W3C Basic Geo definition of SpatialThing in the BP document 14:44:42 frans: a geometry can have spatial relationships, but these are not automatically also spatial relationships of the related spatial thing 14:45:25 ... an explanation is needed of spatial relationships and how they are related to spatial things and geometries. 14:45:50 jtandy: is that written down somewhere? 14:46:06 frans: no, not really. 14:47:19 ... but should be a simple description. We should write it down and ask the group's opinion. 14:47:44 Linda: isn't that description present in geosparql? 14:47:47 frans: not really. 14:48:47 functions, rules and relations (as used in GeoSPARQL) all relate to the same fundamental concept of spatial relationships - and it is this fundamental concept we need to describe in the BP doc 14:49:08 ... topology is a sub-class of spatial relation? 14:49:22 https://en.wikipedia.org/wiki/Spatial_relation 14:50:29 Frans: this page describes topological, directional and distance relationships. 14:50:40 mereological relationship is _not_ a spatial relationship ... anything can be comprised of parts 14:50:40 jtandy: are mereological relationships spatial? 14:52:52 [probably] still need to talk about reconciliation of spatial things ... 14:52:55 jtandy: as editors we now have a clearer picture of what we should put in the BP. 14:53:49 Topic: narrative progress 14:53:56 jtandy: have not seen progress. 14:54:00 Linda: me neither 14:54:05 topic: planning 14:54:13 jtandy: we need a new wd before TPAC 14:54:42 ... so next WD before summer break. 14:55:00 Linda: my summer break is first part of sept 14:55:31 jtandy: End of july for next WD. 14:55:56 ... allowing review by group members 14:56:30 ... vote on 27th of july 14:56:58 ... which means finish by the 20th 14:57:32 ... editorial changes on 28th, 29th. 14:57:34 Linda: agrees 14:58:09 jtandy: we didn't approve the minutes, but we don't have quorum anyway. 14:59:03 ... we need to look through the comments and respond to them. Simeon, Rob Atkinson... 14:59:16 Linda: and the issues? 14:59:41 jtandy: a lot of them will become solved because we now have the narrative and the DWBP we are relying more on than before. 15:01:20 jtandy: frans thanks for your input! 15:02:01 jtandy: closes the meeting 15:02:30 RSSAgent, make logs public 15:02:44 RSSAgent, draft minutes 15:03:50 RRSAgent, make minutes 15:03:50 I have made the request to generate http://www.w3.org/2016/06/15-sdwbp-minutes.html jtandy 15:04:12 RRSAgent, publish minutes 15:04:12 I have made the request to generate http://www.w3.org/2016/06/15-sdwbp-minutes.html jtandy 15:04:28 bye 15:04:30 bye 15:04:34 bye 16:25:54 Zakim has left #sdwbp 17:59:25 jtandy has joined #sdwbp