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

I suspect I can't quite parse your response, but maybe this hints at a broader issue, of nomenclature. In my mental model, we have

- information that identifies a region/___location (civic address, geo coordinates, maybe other unambiguous or local-significance-only names) - the "where" part
- a set of attributes that describe the object identified - the "what" part

Thus, you could consider it a binding: where -> what

This does not bind "places" to "locations" - I admit that I find that terminology very confusing, as normal diction would consider the two synonyms.

Henning

On Nov 19, 2010, at 10:49 PM, Rob Manson wrote:

> Isn't that exactly the reason for the POI standard we're aiming for?
> 
> The POIs are what systems/users can "find".  And they bind Places and
> Things to Locations.
> 
> 
> roBman
> 
> 
> On Fri, 2010-11-19 at 20:35 -0500, Henning Schulzrinne wrote:
>> For private usage, you can name any place, real or fictional, anyway you'd like, but this is pretty likely to be useless for anybody except a narrowly-defined group of individuals. Thus, in order to be useful in a network setting, they either have to be leak-proof or clearly marked with some kind of "___domain" identifier. I have no objection to a group of things/places labeled "Bob's personal POIs", which might include "my home". It's just going be very difficult to automatically locate them except by textual search or other user interfaces.
>> 
>> For the check-in application, you need to have an agreed-upon (unique) name or ___location - how else would somebody else be able to find the same place?
>> 
>> Henning
>> 
>> On Nov 19, 2010, at 7:30 PM, Rob Manson wrote:
>> 
>>> 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 04:16:04 UTC