Re: Action 10 - What Is A POI? - "Place-Oriented Information"?

Hi Henning,

are you really suggesting that Places can only be defined by
civic/street addresses.  To me a Place is simply a Location plus a
"reasonably" well defined boundary that has significance to me (or any
other person) [1].

An example is "the sand bar at North Bondi" [2][3].  When the tides are
right and summer is here then sand bars form at the beach near us.  It's
a magical tropical wonderland for body surfing with crystal clear water.
For me and my family this is a real Place...but it only exists sometimes
and it's definitely not easily referenced by a civic/street address.  In
fact if it did have a civic/street address then that would probably
diminish it in some way 8)

I think that's also the key idea behind Facebook/Google Places and the
whole FourSquare/Gowalla check-in phenomenon.  People can and want to be
able to mark out anywhere as a Place that is significant to them (and
often their tribe).  It's often relative to a Location...but there's
certainly some examples that are relative to other more dynamic things.
e.g. Home is a Place where my family is.


roBman

[1] http://en.wikipedia.org/wiki/Sense_of_place 
[2] http://www.flickr.com/photos/aquabumps/4173063279/in/photostream/
[3] http://www.flickr.com/photos/momentintime/512259802/ 


On Fri, 2010-11-19 at 17:28 -0500, Henning Schulzrinne wrote:
> I'm not sure the distinction is all that helpful. We have two basic coordinate systems that are sufficient to identify places in the real world: civic (street) addresses and long/lat. Both can represent areas large and small, from a single room to a continent. It's obviously sometimes more difficult to map a current ___location to civic ___location, but not always. (For example, indoor ___location is often naturally civic.) On the other hand, descriptions such as "Starbucks in Chicago" are not terribly useful, given their ambiguity.
> 
> Thus, it comes down to 
> - a region with a unambiguous coordinate system
> - a set of attributes or links to those, possibly with a time validity indication
> 
> That's the "database record" or "unit of information exchange". Everything else can then be built on top of that.
> 
> Henning
> 
> On Nov 19, 2010, at 5:17 AM, Rob Manson wrote:
> 
> > Hi Dan,
> > 
> > hrm...surely "Place Oriented Information" is a more confused/confusing
> > term.  I agree with the differentiation that Gary highlighted between
> > Location and Place.  And I agree with what I think you're trying to get
> > at about the separation between "the territory" and the "aspects" of
> > "the map".
> > 
> > But I think it's pretty clear that the group has included all types of
> > "things" that can be represented by POIs including objects that move in
> > space and time (e.g. people, cars, etc.).  Blurring the concept of Place
> > with things like people and cars just doesn't make sense.
> > 
> > That map/territory distinction is really useful though.  POIs are just
> > meta data/records that link arbitrary things to specific Locations
> > (possibly within a specific window in time).  The Location is a real
> > thing (represented in some coordinate system).  The arbitrary thing may
> > or may not be real (e.g. a Place, a person, a car or even a reported
> > incident or an opportunity).  But the POI (in this #poiwg context) is
> > just a way of linking these.
> > 
> > Because it's such a convenient concept people may often confuse it with
> > or collapse it down to the thing it signifies...but in our context this
> > abstract separation is key.
> > 
> > In our AR applications we are generally presenting POIs to users...but
> > not because they actually care about the POI itself...but the "thing"
> > that it re-presents.
> > 
> > 
> > roBman
> > 
> > 
> > On Fri, 2010-11-19 at 10:43 +0100, Dan Brickley wrote:
> >> On Wed, Nov 10, 2010 at 10:11 AM,  <gary.gale@nokia.com> wrote:
> >>> Based on what's been discussed on the public mailing list, I've drawn
> >>> together a definition and description of what constitutes a POI. This will
> >>> no doubt be cause for much discussion and debate but we need a good starting
> >>> point to drive and frame the discussion ...
> >>> Best
> >>> G
> >>> 
> >>> What Is A POI?
> >>> Wikipedia defines a POI as a Point Of Interest ... a "specific point
> >>> ___location that someone may find useful or interesting". But for the purposes
> >>> of this Working Group, we need a more subtle and complex definition.
> >>> A POI is part of a loosely coupled and inter-related geographical terms,
> >>> comprised of (in generalised order of scope and granularity) Locations, POIs
> >>> and Places.
> >>> Location
> >>> A Location is a geographical construct; a physical fixed point on the
> >>> surface of the Earth. It could also be used to describe a fixed point on the
> >>> surface of another celestial body but for the purposes of this Working
> >>> Group, we'll restrict the scope to terrestrial geographies. A Location is
> >>> described by a centroid (a longitude and latitude in a widely adopted
> >>> system, such as WGS-84) and an extent, either a Minimum Bounding Rectangle
> >>> or a vector set. A Location is temporally persistent, it does not generally
> >>> change over time.
> >>> POI
> >>> A POI is a human construct, describing what can be found at a Location. As
> >>> such a POI typically has a fine level of spatial granularity. A POI has the
> >>> following attributes ...
> >>> 1. A name
> >>> 2. A current Location (see the commentary below on the loose coupling of POI
> >>> and Location)
> >>> 3. A category and/or type
> >>> 4. A unique identifier
> >>> 5. A URI
> >>> 6. An address
> >>> 7. Contact information
> >>> A POI has a loose coupling with a Location; in other words, a POI can move.
> >> 
> >> I like the idea of breaking out Location, and Place, and these kinds
> >> of fields seem the right kind of thing. But I'm not yet comfortable
> >> with POI itself. It's a slippery notion!
> >> 
> >> Perhaps the key distinction here isn't quite between 'geographical'
> >> and 'human' constructs, but between terms that directly name aspects
> >> of the world, versus terms that name kinds of information about that
> >> world. The former might range from very geographical, objective,
> >> physical things to more human constructs such as neighbourhood. The
> >> latter makes explicit a level of indirection, and allows the
> >> representation to be talked about explicitly. I think this is why the
> >> concept of POI is somehow slippery when we try to pin it down.
> >> 
> >> For me, POI is much more in the latter case. "Count questions" (How
> >> many Xs...?) can help flesh out the difference.
> >> 
> >> We can sensibly ask:
> >> 
> >> * How many streets, churches, fire hydrants, mountain tops, traffic
> >> blockages, classical music concerts on next saturday, vegan
> >> restaurants; canals or houseboats are there in [some defined notion
> >> of] Amsterdam right now?
> >> 
> >> Each of these definitions is slippery in a different way, and
> >> different agencies, groups etc might define them differently. Yet the
> >> questions remain primarily about the world, albeit expressed using
> >> imperfect, debatable terminology that might need clarifying.
> >> 
> >> If we assume some working consensus of specified definitions (active
> >> churches in the x,y and z faiths; fire hydrants serviced by the civic
> >> authority and known to be recently tested; traffic blockages reported
> >> in the last hour and believed to be still affecting drivers but not
> >> bikes;  etc etc.), each of these questions has factual answers. Now we
> >> would get different answers depending on who we ask, which database we
> >> query, how much money or time we spend asking, what our policy is
> >> towards risk and noise in the data etc., or the exact notion we're
> >> querying for. But the basic scenario is factual questions about the
> >> world, answered in loose or precise form depending on context. Note
> >> that as we get more precise ("reported in the last hour (and not
> >> reported as fixed subsequently)"), characteristics of information and
> >> communication start to sneak into the scenario. This is a good thing -
> >> it means we have useful work to do!
> >> 
> >> If we ask instead:
> >> 
> >> * how many POIs are there in [some defined notion of] Amsterdam right now
> >> 
> >> I don't believe that really has a direct factual answer, without one
> >> crucial qualifier: we need to say which collection of information
> >> we're talking about. How many traffic blockage POIs came back in our
> >> last database lookup? How many Fire Hydrant POIs were described in the
> >> appendix to the 2010 hydrant QA report? How many upcoming classical
> >> concert POIs were attached to that that last email newsletter I
> >> received, or embedded in the concert hall's iCalendar or RSS/Atom
> >> feed? How many POIs were stored on the DVD I've just bought entitled
> >> 'Mountaintops of the Western Netherlands?". That's a different
> >> numerical question to the question of how many mountains are there in
> >> the Netherlands, although the answers are likely to be related. And in
> >> this last case, zero-ish.
> >> 
> >> The same worldly questions and themes crop up in both stories, but
> >> when we talk about POIs we're emphasising the information about the
> >> world as an artifact of direct interest, and in our case technical
> >> standardisation; rather than a transparent means-to-an-end, where the
> >> end is 'information about the world'.
> >> 
> >> By making this indirection explicit, that POIs are informational
> >> entities, I think this eases one of our biggest conceptual problems:
> >> how we deal with different levels of detail. From the example on
> >> weds's call talking about a building, and Gary's desk in the building,
> >> and even some item on that desk of Gary's in that room in that
> >> building in that street. And for the AR guys, for professional GIS,
> >> architecture and city planners alike, these distinctions matter. These
> >> are all identifiable worldly entities, potentially of interest,
> >> potentially described in a variety of standard computer formats. It
> >> makes sense to ask factual questions like 'how many rooms in the
> >> building', but not 'how many POIs'; we can ask 'how many POIs
> >> describing things in that room are there in this particular dataset?'
> >> or 'give me POIs at the granularity of DesktopObject for this area'.
> >> 
> >> This is all a longwinded way of suggesting that "POIs" are better
> >> thought of as aspects of the *map* rather than the *territory*.
> >> However the usual expansion of POI as "Point of Interest" hides this,
> >> and makes us think of POIs as objective characteristics of the world
> >> around us, countable, comparable, etc. without being set in the
> >> context of some description, dataset or map.
> >> 
> >> If we think of POI as "Place-Oriented Information" it makes their
> >> information-dependency much more explicit. I suspect this will help us
> >> think through mashup-oriented issues like "ok, we have one restaurant
> >> but 5 POIs in our system that relate to it; one's a photo, two are
> >> reviews, one comes from a health inspector's report and another is a
> >> 3d building plan". The "POIs" (also pieces of information...) all
> >> relate to the same spatial zone, but they carve it up quite
> >> differently; some treat it (the photos) as an area that reflects
> >> light, some as a service or organization/business that can be
> >> reviewed, paid money, sued, and one as a building occupying physical
> >> space (perhaps with others also inside it).
> >> 
> >> We want a POI standard that allows all these kinds of information
> >> about "the restaurant" to be brought together to serve end-user
> >> scenarios, and to make life easier on the technologists who'll
> >> facilitate this. But we also don't want our POI standard to be
> >> fiendishly rich, modelling fine-grained distinctions explicitly such
> >> as "business" versus "building" within the W3C spec. I expect to see
> >> systems that do draw those distinctions to be able to answer "how many
> >> businesses?" "how many buildings?", "how many businesses in this
> >> building?" kinds of question. I hope they'll be able to answer them in
> >> part from indexing W3C POI descriptions and other extension data or
> >> linked files (CityGML etc). But the more I think about it, the more I
> >> reckon we should reserve POI as a technical term for talking about
> >> those underlying data items used to answer questions, display maps and
> >> AR views and so on, rather than talk as if POIs are actually out there
> >> in the world. The actual points of interest are of course out there in
> >> the world; pieces of place-oriented information live in our computers,
> >> phones, files and data networks.
> >> 
> >> cheers,
> >> 
> >> Dan
> >> 
> >> 
> > 
> > 
> > 
> 
> 
>

Received on Saturday, 20 November 2010 00:30:46 UTC