Re: Spatial context

"All these things are debatable, but rather than debate them it would be good to have agreed upon semantics." Ah, but hard to see how agreement is reached with or without debate! 

I have swum these murky waters for a little while, even wrote papers titled "Event Objects for Spatial History" then "Event Objects for Placial History." 

The problem is that place and location are used interchangeably as answers to 'where?' and their common definitions are circular. I have found it easiest to think of spatial data as formal descriptions of locations (on or near the earth surface for our immediate purposes) -- discrete portions of space described by geometry. Place suggests an occurrence, and place attributes ("placial data") are many. They are normally referred to by toponyms. The geometry (spatiotemporal context?) of places famously change over time (even disappear and re-appear, e.g. Poland), are non-existent (Atlantis), unknown or uncertain (ancient places referred to in texts), vague (Central London), disputed (Tibet), dynamic (the deck of a ship), and so on. Other attributes of Place are entirely experiential and subjective (the NYC of my youth vs. your experience of it; Ed's example of where "my keys" are). These constitute a host of unsolved representation/computation problems. 

I'm guessing the "spatial data" in the list was meant to refer to all of that, and is common usage -- although I prefer "spatiotemporal," or even better, "geographic." I don't understand what is meant by "spatial context" in this conversation but think it does no harm to add it as criteria for considering use cases. I also think we will arrive at a working extensional definition of spatial data by considering all the use cases people consider as concerning spatial data or spatial context. 

best, 
Karl 

------------------ 
Karl Grossner, PhD 
Digital Humanities Research Developer 
Center for Interdisciplinary Digital Research (CIDR) 
Stanford University Libraries 
Stanford,CA US 
www.kgeographer.org 

----- Original Message -----

> I think that the question whether data are spatial data largely depends on
> the data publisher. The designation “Greater London” could be published as a
> text label, in which case it is not spatial data. It could also be published
> as a toponym, in which it is spatial data.

> This discussion seems to point at an important requirement for our work,
> which may or may not be derived from use cases, but still is important: We
> need clear and universal semantics.

> What makes a thing spatial? Does it have to have geometry? Does it have to
> have three dimensions? Does it need to be a terrestial object? Does it need
> to be non-fictional? All these things are debatable, but rather than debate
> them it would be good to have agreed upon semantics.

> At the moment, there are some definitions out there on the semantic web. For
> example, the Location Core Vocabulary defines the concept 'location'.
> Unfortunately the definition is self-referencing: “any location,
> irrespective of size or other restriction”. In other words, it is very open
> to interpretation. Is “Paris” a location (knowing that there are multiple
> locations with that name)? Is Atlantis (fictional) a location? Is Olympus
> Mons (on Mars) a location?

> GeoSPARQL has definitions for the concept 'SpatialObject': “..everything that
> can have a spatial representation” (unfortunately the 'spatial
> representation' part is undefined) and 'Feature': “..equivalent to
> GFI_Feature defined in ISO 19156:2011”. Unfortunately GFI_Feature as defined
> in ISO 19156:2011 is not a web resource and ISO 19156:2011 is not an open
> standard (because you have to pay for it). But it's a start...

> Greetings,
> Frans

> On 2015-02-19 11 :50, Ed Parsons wrote:

> > This is a great discussion and I think it is central to the potentially
> > difficult overlap between the two community perspectives.
> 

> > I'm sure Josh will chip in but I do think we need to recognise that we need
> > to include spatial information for which it is not possible to define a
> > geometry or have linked to as an attribute - This I think is what Josh
> > means
> > by context, I am writing this email from a location within "Central London"
> > although there is not a canonical geometry that represents the shape of
> > central London.
> 

> > This is an example of what Mike Goodchild calls a Platial Problem !
> 

> > This must be in scope, does the current wording around spatial information
> > accommodate it ?
> 

> > Ed
> 

> > On Thu Feb 19 2015 at 10:26:55 Andrea Perego <
> > andrea.perego@jrc.ec.europa.eu
> > > wrote:
> 

> > > Andreas's mail gives me the opportunity to explain the objection I
> > 
> 
> > > raised during the call [1] about the proposal of adding "spatial
> > 
> 
> > > context" into scope question #1 [2].
> > 
> 

> > > My main concern is that the use of "spatial context" in the scoping
> > 
> 
> > > question may be confusing, and probably unnecessary.
> > 
> 

> > > In my understanding, spatial context is specified through spatial data
> > 
> 
> > > - i.e., it denotes one of their possible uses. So, "spatial data"
> > 
> 
> > > should be inclusive enough - it would cover spatial data as a whole,
> > 
> 
> > > irrespective of their use.
> > 
> 

> > > Thanks!
> > 
> 

> > > Andrea
> > 
> 

> > > ----
> > 
> 
> > > [1] http://www.w3.org/2015/02/18-sdw-minutes.html
> > 
> 
> > > [2] http://www.w3.org/2015/spatial/wiki/Scope_questions_and_Requirements
> > 
> 

> > > On Wed, Feb 18 , 2015 at 10:10 PM, Andreas Harth < harth@kit.edu > wrote:
> > 
> 
> > > > Hi,
> > 
> 
> > > >
> > 
> 
> > > > the issue I had with the term "spatial context" is that I did not know
> > 
> 
> > > > what the "context" part was supposed to mean.
> > 
> 
> > > >
> > 
> 
> > > > If I understood Josh correctly, he mentioned that a geometry,
> > 
> 
> > > > a place description or a spatial feature should be referenceable
> > 
> 
> > > > in data.
> > 
> 
> > > >
> > 
> 
> > > > If "spatial context" does mean that, I'm fine with the phrasing of
> > 
> 
> > > > the scoping question.
> > 
> 
> > > >
> > 
> 
> > > > Cheers,
> > 
> 
> > > > Andreas.
> > 
> 
> > > >
> > 
> 

> > > --
> > 
> 
> > > Andrea Perego, Ph.D.
> > 
> 
> > > Scientific / Technical Project Officer
> > 
> 
> > > European Commission DG JRC
> > 
> 
> > > Institute for Environment & Sustainability
> > 
> 
> > > Unit H06 - Digital Earth & Reference Data
> > 
> 
> > > Via E. Fermi, 2749 - TP 262
> > 
> 
> > > 21027 Ispra VA, Italy
> > 
> 

> > > https://ec.europa.eu/jrc/
> > 
> 

> > > ----
> > 
> 
> > > The views expressed are purely those of the writer and may
> > 
> 
> > > not in any circumstances be regarded as stating an official
> > 
> 
> > > position of the European Commission.
> > 
> 

> 

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