Re: thoughts towards a draft AR WG charter

Hi Matt, all,

On Fri, Jul 30, 2010 at 7:34 PM, Matt Womer <> wrote:
> Hello everyone,
> First, I'm glad to see this discussion going on, this is great!  My apologies for not sticking to the +/-1 format.  As Christine mentioned I'm the W3C staff person who will be helping out this group.  There's been a lot of great discussion, and I'd like to offer my two cents before we dig into drafting a charter.

I pretty much agree with your analysis and suggested direction, in
particular with forming a POI group rather than one themed and branded
solely in terms of 'augmented reality' (much as I love AR...).

As with most such efforts, the toughest piece will be scoping. You
draw attention to the slipperyness of the concept of a "POI". I wonder
whether it might be instructive to collect negative as well as
positive test cases, to help scope the problems the group will be
initially addressing.

Which of the following can usefullly be treated as POIs? (some cases
from top of my head; I don't argue they're primary, just that it would
be good for folk to start a WG with roughly similar instincts as to
what they're interested in describing)

* a particular living person (eg. me)
* a particular dead person (eg. Marco Polo)
* a particular probably-fictional person (eg. Robin Hood)
* an event, eg. birth of Marco Polo
* another event - the Battle of Hastings
* another - "World War Two"
* a specific purchasable thing, eg. some particular inner tube fitting
a certain kind of wheelchair wheel (which is on a particular shelf of
a particular shop somewhere)
* a school considered as an educational institution
* a school considered as a physical building
* a rock concert that is happening next week
* a classical concert that was supposed to happen last week, but was cancelled
* a road blockage
* a special offer on tuna pizzas at a particular chain of pizza shops
NEXT WEEK ONLY, to celebrate international Tuna Not Extinct Yet Day
* a piece of software considered as an abstract work
* a piece of software, considered as a particular boxed product for
sale in some particular shop
* a performance of a particular song during a particular concert at a
particular time
* a particular copy of a particular book, on some shelf in a shop
* a particular copy of a particular book, on some shelf in a museum
* a particular tree
* a regular weekly face-to-face meeting of a particular named social group
* a specific occurance of a weekly face-to-face meeting of some group of people
* a phone conversation (or either 'end' of it)
* a flood
* a power-cut
* an outbreak of Bird Flu
* an electoral region
* a historical electoral region that is no longer current
* Palestine
* a famous painting
* the industrial revolution
* a geo-stamped a twitter posting (er, tweet)
* a geo-stamped photo on Flickr
* the place shown in a geo-stamped photo on Flickr
* the scene depicted in a famous painting
* a fictional scene from a famous film
* the birthplace of a fictional person
* British Telecom
* BP

As I rummage around for examples, I'm left feeling that absolutely
anything which might be ascribed some form of spatial location is a
legitimate 'point of interest', and that when I look for the kinds of
things that might be utterly NOT in scope for POIs, we only have pure
abstractions (a poem; some software 'in the abstract'; the number 7)
to deal with. In other words, of all the countless and infinitely
varied things in the world, most of them are in-scope. And while I
guess we all knew this, it is quite humbling and scary when you start
trying to list varied examples. Scary because it will be pretty hard
for the WG to know when they're "done".

I won't go thru the above list one by one, but roughly my "is this in
scope?" intuitions were most challenged when thinking about things
whose current right-now reality might be questioned: events that
might've happened but didn't; things in the past; things whose
fundamental definitions are contested; processes. On the other hand,
events (although slippery) are fine things to know locations for;
there are tourism, cultural heritage and educational reasons to want
to record locations of birthplaces and other events. And there are
practical reasons why we might want this information to show up in the
same information environment as other "POIs".

> Looking at the AR workshop report [1], it states two aims for a new WG, one of which is:
> "To develop a standard for representing Point of Interest (POI) data."

Actually I quite like that, as it's a bit sneaky and avoids directly
asserting that there are 'things' which are points of interest. There
is "POI data", ... information relating to points of interest.

Thinking through some of the examples above, I'm left with the
impression that a big part of the problem is relational.  Perhaps x is
a place that was possibly-maybe-likely the birthplace of Marco Polo?
Then who is Marco Polo? Well he's the 'primary subject' of a certain
Wikipedia page, the author of a certain well known book, etc etc. In
this view the geographical fragment is just a piece of a larger
network of factual data. And the uncertainty factor comes from
documented disputes rather than fuzzy GPS data.

My personal hope is that we see POIs as an artifact and place-oriented
view into this kind of Web of factual data, and consequently can take
an ambitious approach to scoping and extensibility in which the
species of a tree, the number of pupils of a school etc are all
relevant information and discoverable within the POI description. And
[crucially if our little screens aren't to fill up with clutter]
available to use as properties for filtering on.

> This seems like a straightforward statement, but I've noticed that it seems like we don't have a common definition of POI.  Are they represented by a single set of coordinates?  Are they only locations fixed in space relative to Earth?  What is the information that pertains to them?  I'd like to offer a straw-man definition of POI for the purposes of discussion here, lets bat it around and see if maybe some of the issues get resolved along the way.
> [[
> A Point of Interest is an entity which has a location and about which information is available.
> ]]
> That's hopefully not very controversial, though it does raise more questions:  What is a location?  What information?  So let me take a shot at those definitions too:
> [[
> A location is a point in space that may be expressed in a geodetic system (e.g. lat/lng in WGS84), or relative to something else (e.g. "near", "in"), or a qualitative expression (e.g. "indoors", "near public transportation", "unknown").
> ]]
> This is more controversial as it includes complex notions of location that are probably beyond what people include in their definition of the term POI, but I think it is more useful in this context.  I don't know that it covers all cases, and I don't know just how much of that is ready for standardization, but it's a starting uh, 'point'.

'Point' has an awkward ambiguity; it suggests an infinitely small
thing, but also something like 'place or location'. But perhaps you do
mean a bit of both of those?

> What information might we want to attach to such locations?  Well, anything, and that should be possible in whatever we do, but there is a set of very useful information that we could likely agree would very useful to standardize: name, shape, and temporal information.
> Name seems fairly straightforward and is probably something we can adopt from elsewhere.
> Shape information, on the other hand, is more complex.  For starters, not all POIs have a shape (e.g. points such as 'center of this room', 'corner of Mass Ave and Vassar St'), or maybe a point is a shape here?  Some POIs may have a shape that's sufficiently described by a simple 2d circle, bounding box or polygon (e.g. "Empire State Building" may have a rectangle representing it's base at ground level), or 2d with a height (e.g. "the Empire State Building" is a rectangle that is 443 meters tall).  Some POIs might best be represented by a three-dimensional model of varying levels of complexity and detail  (e.g. "the Empire State Building" is a rectangle with a pyramid on top or a complex CAD-like model).  I'm not sure we can standardize each of those cases immediately, but a polygon with a height seems doable, and again could be something that is available elsewhere.

The Empire State Building isn't itself a rectangle with a pyramid on
top; but in some circumstances it's useful to describe it as such. I
suggest one thing we'll run into quite early (due to the generally
aggregation-friendly nature of geo data) is that we'll encounter
multiple independent descriptions of the same real-world thing, but
[awkwardly] at different levels of abstraction. So a blob on a map
might 'be' the empire state building; but so might a detailed 3d model
+ floor plan. Should it be a requirement that the POI data format
handle the ability to express this same-ness across levels of detail?

> Then there's the notion of time.  All of the information about a POI may change over time: the POI could move, its shape or name could change, it could cease to exist, or be created in the future.  The ability to add temporal information to each of the properties would give us quite a bit of power.  Perhaps this isn't required, but I think it opens a whole set of possibilities that could be difficult otherwise.

I also found myself special-casing time. But it's a horrible can of worms :)

> Add "Web-style extensibility" (as Dan called it [2]) to these three concepts (location, shape, and name each possibly annotated with time information), and we've got a pretty flexible definition of a POI that could describe traditional POIs such as "Times Square", as well as more complicated ones like a traveling circus, or even less obvious ones like this pen on my desk.

I suspect we're going to find it harder to think of things that are
*not* POIs. But this broadness is quite inevitable, so best to
confront it up-front...

> If we could standardize these properties, then we'd have a powerful format that could be used in AR as well as other applications.  If we take advantage of extensibility, we could build a vocabulary for common properties right out of the gate (e.g. description, owner, open/close hours, etc).  Meanwhile, we could also work on covering the more complex possibly AR specific properties such as an image to be used in image recognition property, or other properties that may be used for the non-location-based query use cases.  With these things, we would cover the POI action in the report.  We could of course address other topics, like triggers.  (I haven't addressed that in this message as I'm not 100% sure I understand.  Sometimes they read like complex queries, other times like the POI itself is the trigger.)

Re triggers, I'd like to understand how that notion compares to what
Google Earth / KML has, as 'network links'. Is it the same idea?

> What would this mean for where the work goes?  Well, given how useful a POI format is beyond AR, and the amount of work, my straw-man proposal would be to create a POI WG with a primary use case of AR that would develop a POI Recommendation, AR vocabularies, etc.  In the future, as the core POI work winds down then perhaps recharter as an AR specific WG.

+1 on most of that, only concern being re 'perhaps recharter as AR specific'

Re AR-specific group, I think AR will always be the crossroads and a
kind of 'inspiration engine' for creative use cases. But next year's
AR-inspired work might be for eg engaging with Voice browsing and
recognition, or with barcodes/qrcodes, or APIs for image recognition,
or reviewing the HTML5 / webapps APIs from AR perspective...i.e.
something quite different each time. If W3C had a flavour of WG that
was a bit like an interest group, incubator and coordination group
rolled into one, it could fit quite well there! (actually I think we
have similar need in SocialWeb world....).

> So, that's my thoughts, let me know what you think.

Good stuff :)


> Thanks,
> -Matt Womer
> W3C staff, Ubiquitous Web Activity Lead
> [1]
> [2]

Received on Saturday, 7 August 2010 15:55:38 UTC