- From: Phil Archer <phila@w3.org>
- Date: Mon, 6 Jun 2016 10:12:39 +0100
- To: SDW WG Public List <public-sdw-wg@w3.org>
And, amazingly, the minutes of last week's BP and Spatial Ontology
meeting are at https://www.w3.org/2016/06/01-sdwbp-minutes with a text
snapshot below.
[1]W3C
[1] http://www.w3.org/
Spatial Data on the Web BP Sub Group Teleconference
01 Jun 2016
See also: [2]IRC log
[2] http://www.w3.org/2016/06/01-sdwbp-irc
Attendees
Present
BartvanLeeuwen, Linda, frans, ByronCinNZ, eparsons,
joshli, MattPerry, roba, billroberts, ClausStadler,
AndreaPerego
Regrets
Payam, Jeremy, PhilA
Chair
Linda
Scribe
billroberts
Contents
* [3]Topics
1. [4]Progress of BP Narrative 2
2. [5]spatial ontology
* [6]Summary of Action Items
* [7]Summary of Resolutions
__________________________________________________________
<frans> Only Dutch people on webex
<Linda> Ed, Bill, will you join the webex?
<eparsons> Just switching meetings
<Linda> present
<Linda> present?
<scribe> scribe: billroberts
<Linda> [8]https://www.w3.org/2016/05/18-sdwbp-minutes
[8] https://www.w3.org/2016/05/18-sdwbp-minutes
Proposed: approve minutes of last meeting
<BartvanLeeuwen> +1
<Linda> +1
0 - wasn't there
<eparsons> 0 sorry
<joshli> +1
<MattPerry> 0 - not there
<frans> +0 (but they look fine)
<ByronCinNZ_> +1
RESOLUTION: minutes approved
<Linda> [9]https://www.w3.org/2015/spatial/wiki/Patent_Call
[9] https://www.w3.org/2015/spatial/wiki/Patent_Call
Progress of BP Narrative 2
<Linda> [10]https://www.w3.org/2015/spatial/wiki/BP_Narrative_2
[10] https://www.w3.org/2015/spatial/wiki/BP_Narrative_2
BartvanLeeuwen: Nicky and Bart have been working further on it.
Should be possible to align the work of the Dutch working group
and this group
Linda: would be useful to get feedback from the Dutch group on
the narrative
BartvanLeeuwen: the Dutch group would like to produce some
guidance. For this group, would be good to show that external
people have used it
Linda: Bart to ask Nicky to share feedback via the mailing list
or by editing the wiki page
Linda: has edited the language to reduce the amount of jargon
<Linda> convert a coverage to a Feature dataset using the
�typical� Web environment of a javascript engine
Linda: has edited item (3). Question to working group on that
particular sentence
BartvanLeeuwen: this might be to do with OpenLayers - taking
feature data and putting it on a map
<joshli> was the idea to do the conversion with a javascript
engine or access a processing API?
BartvanLeeuwen: but that might not be what Jeremy meant when he
wrote it
Linda: thinks he meant to process coverage data and detect
features
eparsons: questioned Jeremy on this point as this seemed not
something that a web developer would do directly
... perhaps the details don't matter, other than the high level
point that the developer does something to achieve a purpose.
We don't need to be specific about how
joshli: 3 pieces to this. (1) Processing can be accessed via a
javascript library (though perhaps more liekly to be accessing
an API).
... (2) common task to take an image or raster and have someone
draw features on it, eg via crowdsourcing
... (3) corollary is to be able to link the derived feature to
the source raster data
<Linda> billroberts: made some edits in section 5, happy to
take feedback
<Linda> ... described minimum stuff to do and more advanced
stuff census data publishers might do, including data cube
stuff
<Linda> .. what's the take on including examples, I included
one from the Scottish govt statistics.
Linda: in favour of including examples
<eparsons> +1 for examples
<frans> We could look at what Eurostat provides too
<Linda> ... happy to add more examples
Linda: welcomes input from others on the narrative - editors
can't do it all themselves
eparsons: has worked on item 6 (evacuation plan)
... importance of human readable as well as machine readable
presentation of data
<roba> ed - so if some people will be humans.. what are the
other peple?
Linda: has talked to Payam this week and he intends to help
Josh on topics 7 and 8.
<eparsons> roba how machine overlords
<Linda>
[11]https://www.w3.org/2015/spatial/wiki/An_agreed_spatial_onto
logy
[11] https://www.w3.org/2015/spatial/wiki/An_agreed_spatial_ontology
spatial ontology
Linda: there has been discussion on an agreed spatial ontology.
Should it be a new one, or should it be improvements to an
existing one, eg GeoSPARQL
joshli: presents thoughts on the spatial ontology.
... so far we have been focusing on how to do geometry
... looking at updating the GeoSPARQL approach to feature
geometry
... the issues are (1) there should be some means to use and
reuse multiple geometries. There are very simple spatial
ontologies that say feature = geometry = encoding, but there
are many use cases that require these to be separated
... geometry should be a first class object so that attributes
of it can be captured
... so the geometry has to be disjoint from the feature
... and the feature should be disjoint from the spatial object
... a type of spatial object would be a geometrical object
... which would enable topological relationships without having
to talk about coordinates
joshli (continued): we also want to make it very simple for eg
web developers to add information to a spatial object, eg
simply lat,long coordinates
scribe: want to find a way to be rigorous when we want to and
simple when we want to
... It's not yet clear how to do that and which mechanisms
would be best. SHACL?
... in GeoRSS 2005, we just stated equivalence of different
forms
... One additional aspect is that there should be different
serialisations of coordinate positions for a geometry
... Given a geometry with particular resolution and coordinate
system, we want to use the GeoSPARQL property as a particular
serialisation, eg asWKT, asGeoJSON, asGML. Can assert that they
are mathematically the same but expressed in different formats
... that's another issue to resolve. [End of Josh's overview]
eparsons: agrees with Josh's thoughtful approach. We should
look at this starting from a simple approach. This is spatial
data **on the web** and many use cases are simple
... There are also common use cases about spatial information
that may have no defined geometry. We should include that in
our thinking
... Someone wants to talk about London but doesn't need to
define the geometry of it
Joshli: Matt Perry has been thinking about this. eg you might
want to talk about London as a two dimensional region and say
that something else is inside it, without specifying details
eparsons: 'London is in England', 'England is in Europe' etc
are useful pieces of information
joshli: those are assertions about the spatial nature of those
things, even if not talking about geometry explicitly
MattPerry: been looking for a simple approach to this: making
assertions about a feature rather than adding new classes to
the hierarchy
... it may well make sense to add Spatial Object as a new
class, but we need to eb careful not to break what we already
have
frans: Simplicity should be paramount in this context
... if we can put in good foundations for the basics of
geometry that would be a step towards simplification
... the foundation (which in itself might not be simple) can
hopefully build bridges between different representations on
the web
... Is this an opportunity to start cooperating on developing a
new ontology?
joshli: answer to that is 'yes'. Josh is working on one and
would be happy to host drafts
frans: Coverage people had a discussion
bill: (actually that was teh SSN group)
joshli: SSN group talked about Webprotege as a tool
roba: I'm working on describing hierarchical relationships in
data cube dimensions
... linked data web is very heterogeneous. Often relies on
assumed rather than explicitly declared knowledge. Many
different terms used by different people. There is a lot of
misuse of vocabularies
... so there is a need for a best practice as there are too
many different ways of doing it
eparsons: we should think more broadly than just geometries,
but also think of relationships between features that rely on
other aspects of them than geometry
joshli: I've been focusing on geometry so far as that seemed to
be the pain point
... but interesting to consider other things
... How do we distinguish between spatial relationships and
(non-spatial) feature relationships?
... but this can get very complicated.
eparsons: perhaps we can at least note our aspiration to go in
that direction, while noting the concern about complexity of
that
... it's natural to get het up about geometry, but many web
developers take a more 'place-based' than 'space-based' view of
the world
joshli: noted in his conversation with Matt, than many
relationships are not space based, eg 'part of' relationships
... useful to describe equivalence between different kinds of
relation
<Linda> oops, I was actually talking but muted...
frans: audience could include, for example, people at say
Google working on artificial intelligence, data mining, etc
might benefit from spatial data on the web having common
geometrical foundations to make it more processable
linda: asks Frans - is there anything in the use cases about
this?
frans: yes, lots relating to defining and consuming geometry
roba: noting conversations in the SSN group, about how to
modularize vocabularies
... so can have a simple basic ontology then add in more
sophisticated modules if you want to do reasoning
<AndreaPerego> About UCR & spatial ontology, there's also some
about spatial relations -
[12]https://www.w3.org/TR/sdw-ucr/#SpatialRelationships
[12] https://www.w3.org/TR/sdw-ucr/#SpatialRelationships
Linda: can we categorise our requirements into 'simple' and
'complex' ?
eparsons: in response to Frans on AI, data mining etc - the
geometry is not always relevant to that. More important is
relations between features. The relation is 'London is in
England'
... second point is a more operational one. How are we going to
get this work done? Is it part of the BP, or is it a separate
deliverable that needs to be managed and resourced
... don't want to lose focus on the BP while working on the
spatial ontology
Linda: yes that needs further discussion. In my mind it is a
separate thing
joshli: agrees that it should be separate to the BP
deliverable.
... it could be an OGC thing that could be cited in the best
practice
... but need to consider the process for that. Perhaps a
charter for a GeoSPARQL working group
... should development of ontology be part of the SDW activity?
Maybe SDW can set requirements and the drafting of it could be
in OGC context perhaps
<eparsons> +1 to josh's plan req from here - doc produced via
OGC process
joshli: Also, useful to look at the SSN modularity approach as
a pattern, but is that parallelisable
<Linda> +1 to josh's plan
<AndreaPerego> +1 to RDFS for core, and more sophisticated
formalisation for extensions.
frans: on modularity, GeoSPARQL is already modular in a
functional sense. We would want a future version of GeoSPARQL
to be compatible with the existing version, so would keep
existing modularization pattern
... a risk of the ontology development being in the OGC area
might be a loss of input from W3C perspective
<eparsons> +1
<AndreaPerego> +1
<Linda> +1
<MattPerry> +1
Linda: who would be interested on working on this ontology?
<ByronCinNZ_> +1
<joshli> +1
<frans> +1
<AndreaPerego> +1
<roba> +1
<eparsons> thanks billroberts Good Job !!
Linda: will take this discussion back to plenary group next
week
<AndreaPerego> Thanks, and bye.
<eparsons> thank Linda
Meeting closed
<frans> Thanks all, have a good day
<joshli> bye bye
bye
<MattPerry> bye
<Linda> bye
Summary of Action Items
Summary of Resolutions
1. [13]minutes approved
2. [14]minutes approved
[End of minutes]
__________________________________________________________
Received on Monday, 6 June 2016 09:12:38 UTC