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Re: thoughts towards a draft AR WG charter

From: Rob Manson <roBman@mob-labs.com>
Date: Sat, 31 Jul 2010 16:06:31 +1000
To: Matt Womer <mdw@w3.org>
Cc: public-poiwg@w3.org
Message-Id: <1280556391.3348.1187.camel@localhost.localdomain>
Hi Matt,

> First, I'm glad to see this discussion going on, this is great!


NOTE: I apologise for the double post earlier.  I thought the moderation
system had eaten my message and it's such a great discussion I just had
to hit send again 8)

> 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."

I may be missing a bit of context since I didn't attend...but I feel
this could end up being a very limited and short term statement that
undershoots the potential of this whole discussion.  To me this would be
analogous to HTTP having only specified support for HTML documents 8/
I'll expand this a little below...

> 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.
> ]]

I don't disagree with this statement at all.

> [[
> 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'.

Well...if we did use the "trigger" model then I'd express this as the
following RDFa style triplet:

        this [location] is a [trigger] for [this information]

POIs in this format would then become the archetypal AR relationship.
The most critical and common subset of the broader relationship:

        this [sensor data bundle] is a [trigger] for [this information]

In the standard POIs case the minimum [sensor data bundle] is "lat/lon"
and then optionally "relative magnetic orientation".

> 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.

Well...this relationship should definitely be open to all forms of
geometry - point, line, area, volume, cluster and manifold/entry point.
And this should have an optional relationship to time as well.

I would also suggest that we allow a global point of origin (e.g. the
earth) which may be implied where not relevant.  But the scope of this
discussion is essentially futuristic and should not be limited to just
our physical world 8)

In decoupled/loosely coupled way a POI may just be the point of origin
for other related geometries too.  This decoupling allows multiple
presentation formats.  e.g. in it's simplest form just a list format and
in it's most complex a rich and dynamic 4D entity.  Both of these
extremes are just "related" to the same origin POI and simply different
(and accessible) expressions of the same concepts.

> 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.

Time is essential.  It may be optional (e.g. default is persistent
through time).  But I believe it is definitely essential.

> 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 think this is where the linked data concepts come in.  All that we've
learned in that space should allow us to make our approach here
flexible, extensible and eloquent.  I think this also provides support
for broadening the definition beyond just that of a POI.

> 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.)

Sorry, this is where I have to -1 
I agree POIs are practically useful right now and have captured broad
market appeal.  But I think without much effort at all they can clearly
be defined as a small but critical subset of a broader concept that will
leave our path open to a much richer and expressive set of technologies.

> 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.

I'd also be interested in a discussion of how this work impacts the
other WGs/etc.  Perhaps this has already been covered, but from my
perspective the Geolocation API (obviously)[1], Camera/Capture API
[2][3] and Sensors Networks [4] just to name a few are all impacted.

[1] http://www.w3.org/2008/geolocation/ 
[2] http://www.w3.org/2009/dap/ 
[3] http://www.w3.org/TR/2010/WD-capture-api-20100401/ 
[4] http://www.w3.org/2005/Incubator/ssn/charter 

> -Matt Womer
> W3C staff, Ubiquitous Web Activity Lead

I hope you don't start to think I'm just plain argumentative...but my
personal research project proposes that Pervasive is a more appropriate
and Humanist term than Ubiquitous http://ht.ly/2j8Rs
Sorry...I just have to call that out whenever I see people using the
Weiser's term 8)

Received on Saturday, 31 July 2010 06:09:11 UTC

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