Dear Alan,
Well, I cannot really argue with that.
But one thing is for sure: the ref that Jake suggested is listed by ISI. See
attached pdf.
All the best,
Rui
> -----Original Message-----
> From: [log in to unmask] [mailto:[log in to unmask]] On
> Behalf Of Alan Penn
> Sent: 09 March 2005 21:00
> To: [log in to unmask]
> Subject: Re: [SPACESYNTAX] Publically available standard test cases
>
> Umm, no. I was answering your question... :-) Alan
>
>
> Dear Alan,
>
> Is this space syntax for 'Dear Rui, you have a point.'
>
> Or should we agree that the arguments are getting circular once again?
>
> Rui
>
> > -----Original Message-----
> > From: [log in to unmask] [mailto:[log in to unmask]] On
> > Behalf Of Alan Penn
> > Sent: 09 March 2005 18:05
> > To: [log in to unmask]
> > Subject: Re: [SPACESYNTAX] Publically available standard test cases
> >
> > Newton did
> >
> > Alan
> >
> >
> > > -----Original Message-----
> > > From: [log in to unmask] [mailto:[log in to unmask]]
On
> > > Behalf Of Rui Carvalho
> > > Sent: 09 March 2005 18:00
> > > To: [log in to unmask]
> > > Subject: Re: Publically available standard test cases
> > >
> > > Dear Bill, Alan,
> > >
> > > Sorry to be stupid, but I still can't find a satisfactory
methodological
> > > discussion (Alan, maybe this is your point) -at least not in 'Natural
> > > movement' which I have here. P 42 has a very short discussion, but
there
> > > are
> > > no references to any other papers and (at least to my reading) the
> method
> > > is
> > > not detailed.
> > >
> > > The question is: can we do science without properly peer refereed
> > > methodology?
> > >
> > > Rui
> > >
> > > > -----Original Message-----
> > > > From: [log in to unmask] [mailto:[log in to unmask]]
> On
> > > > Behalf Of Alan Penn
> > > > Sent: 09 March 2005 17:51
> > > > To: [log in to unmask]
> > > > Subject: Re: [SPACESYNTAX] Publically available standard test cases
> > > >
> > > > Rui,
> > > >
> > > > You are right, of course, that everything I say doesn't appear in
any
> > > one
> > > > place or I would just have cited a reference. The parts of the
> > > observation
> > > > method that are most relevant in any case - eg. Observation methods,
> > > sample
> > > > times and number and location of observations etc. are detailed in
the
> > > main
> > > > texts (eg. P.347 of Ortuzar et al. Travel Behaviour Research:
Updating
> > > the
> > > > state of play, Pergamon, 1998.), but the relationship between
methods
> > > and
> > > > possible errors and the processes one puts in place to control these
> > > errors
> > > > tend to only exist in the protocols. One of the problems with
> > > publications
> > > > in our field is that unlike biology they lack extensive 'methods'
> > > sections.
> > > > There tends to be little discussion of these issues in any of the
> > > > traffic/movement literature. This may be an area where we know
enough
> > > about
> > > > sampling of pedestrian movement and the errors involved in the
process
> > > to
> > > > make a paper of its own, although I suspect that most journal
editors
> in
> > > the
> > > > field would find the issue a bit dry and uninteresting. What do
people
> > > > think?
> > > >
> > > > Alan
> > > >
> > > >
> > > > >
> > > > > Dear Alan,
> > > > >
> > > > > Thanks for the interesting points. To my knowledge this detailed
> > > > > discussion
> > > > > remains absent from the refereed literature -am I missing
something?
> > > > >
> > > > > Rui
> > > > >
> > > > > P.S.: So that there are no further misunderstandings, by 'refereed
> > > > > literature', I mean journals indexed by Thomson ISI (this leaves
out
> > > SS
> > > > > Symposia). By 'detailed discussion' I mean a full discussion on a
> > > > > methodology for observation counts, with references to previous
work
> > > (not
> > > > > just SS).
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: [log in to unmask]
> [mailto:[log in to unmask]]
> > > On
> > > > > > Behalf Of Alan Penn
> > > > > > Sent: 09 March 2005 16:55
> > > > > > To: [log in to unmask]
> > > > > > Subject: Re: [SPACESYNTAX] Publically available standard test
> cases
> > > > > >
> > > > > > Just to be clear on methodology, Sheep's 'lunchtime observation'
> at
> > > the
> > > > > last
> > > > > > symposium was fun, but a single 5 minute observation does not
> > > provide
> > > > > good
> > > > > > data on urban pedestrian flow rates, even if all the observers
can
> > > be
> > > > > relied
> > > > > > on to observe for 5 minutes rather than some for 5.3 minutes.
> > > > > >
> > > > > > In the London studies that Bill referred to earlier in this
thread
> > > the
> > > > > > procedure was to observe each segment of a whole area for 5
> minutes
> > > > > within
> > > > > > each 2 hour period of the day between 8am and 6pm and re-observe
> the
> > > > > > following day. A total of 10 x 5 minute observations were
carried
> > > out
> > > of
> > > > > > each space. Within any single time period (say 10am-midday)
there
> > > were
> > > a
> > > > > > total of 2 x 5 minutes of observations on different days.
> > > > > >
> > > > > > Rui points to the issue of experimental error on the part of the
> > > > > observer
> > > > > > and the timing of an observation. I believe that with training
and
> a
> > > > > watch
> > > > > > that in general observers do much better than 10 seconds at the
> > > start
> > > > > and
> > > > > > the end of the period, however errors will still be made. The
> result
> > > of
> > > > > > repeat observations however should be to reduce these errors as
> > > > > sometimes
> > > > > > they may be a second or two short and others may be a second or
> two
> > > > > long.
> > > > > > Overall, repeating reduces this type of timing error.
> > > > > >
> > > > > > Noah points to the issue of whether a 5 minute sample is
adequate
> > > for
> > > > > low
> > > > > > levels of movement. The point here is that our total observation
> > > times
> > > > > are
> > > > > > 50 minutes (for all day averages) rather than 5 minutes. There
are
> > > > > spaces
> > > > > in
> > > > > > observation studies that do record 0 passers-by in 50 minutes.
> Quite
> > > > > > honestly, by the time you have stood in one of these spaces for
> that
> > > > > long
> > > > > > you are pretty sure that 0 is a good estimate of its level of
use.
> > > > > >
> > > > > > Clearly, the time period by time period data are based on only
20%
> > > of
> > > > > the
> > > > > > full sample, however tests of the errors involved in sampling -
> ie.
> > > how
> > > > > good
> > > > > > is any single time period as an estimate of the all day average
-
> > > showed
> > > > > > that the 10 minutes observations were within 95% confidence
> limits.
> > > In
> > > > > > general, where one is particularly interested in flows in very
low
> > > use
> > > > > areas
> > > > > > (housing estates for example) one increases the total length of
> > > > > > observations.
> > > > > >
> > > > > > There are other forms of experimental error that crop up from
time
> > > to
> > > > > time.
> > > > > > In very high use spaces - Oxford Street at Christmas for example
-
> > > it
> > > > > can
> > > > > > get very hard to count the number of people present - there are
> just
> > > too
> > > > > > many. The standard approach here is to first split the task, for
> > > example
> > > > > by
> > > > > > counting only one pavement at a time, and then by counting only
> one
> > > > > > direction of movement at a time. The positive side of
> over-crowding
> > > is
> > > > > that
> > > > > > people move more slowly, and that a shorter observation period
> (say
> > > 2
> > > > > > minutes for each pavement/direction) will be adequate to give a
> good
> > > > > > estimate. The point here is that counting errors will still be
> made,
> > > > > but,
> > > > > as
> > > > > > previously, mis-counting by a person or two is as likely to be
> > > reversed
> > > > > at
> > > > > > the next repeat observation. In this situation though, as a
> > > proportion
> > > > > of
> > > > > > the total flows involved, the errors will be very small, and the
> > > higher
> > > > > the
> > > > > > flow the smaller the proportional error resulting from
miscounts.
> > > > > >
> > > > > > The main risk involved in this kind of sampling is that there
> might
> > > be
> > > > > some
> > > > > > kind of systematic bias - the observer who forgets his watch but
> > > doesn't
> > > > > > tell you for example. Since most possible systematic biases are
> > > related
> > > > > to
> > > > > > the individual observer the process we use involves training and
> > > quality
> > > > > > checking. We train and instruct observers to ensure that they
know
> > > what
> > > > > to
> > > > > > do and that they all apply consistent criteria. Then we ensure
> that
> > > the
> > > > > same
> > > > > > spaces are observed by at least two different observers and we
> check
> > > > > their
> > > > > > results against each other. The presence of the check, and the
> > > knowledge
> > > > > of
> > > > > > its existence on the part of the observers acts as a peer
pressure
> > > > > measure
> > > > > > to ensure compliance with the protocols. If you find that
> observers
> > > A
> > > > > and
> > > > > B
> > > > > > systematically disagree, you go on to check each against
observers
> C
> > > and
> > > > > D.
> > > > > > It is pretty easy (but a very rare occurrence) to detect a rogue
> > > > > observer,
> > > > > > confirm with them what they were doing wrong and if need be
> discard
> > > > > their
> > > > > > data.
> > > > > >
> > > > > > Nothing in the field of human research is infallible, but I
think
> > > that
> > > > > the
> > > > > > observation data we get this way are pretty robust. One of the
> > > things
> > > > > that
> > > > > > leads me to think this is that where we have re-observed the
same
> > > > > systems
> > > > > > after a period of years, and where there have been no
> morphological
> > > > > changes
> > > > > > in the interim, the two sets of observations correlate to a very
> > > high
> > > > > degree
> > > > > > (r^2 ~ .9). This suggests that the amount of error or noise
> > > resulting
> > > > > from
> > > > > > the observation methodology is low.
> > > > > >
> > > > > > Alan Penn
> > > > > > Professor of Architectural and Urban Computing
> > > > > > The Bartlett School of Graduate Studies
> > > > > > University College London
> > > > > > Gower Street
> > > > > > London WC1E 6BT
> > > > > > +44 (0)20 7679 5919
> > > > > > [log in to unmask]
> > > > > > www.vr.ucl.ac.uk
> > > > > > www.spacesyntax.org
> > > > > >
> > > > > >
> > > > > > Noah wrote:
> > > > > > >
> > > > > > > The volume of traffic at each gate matters as well. Small
> > > variations
> > > > > in
> > > > > > > time will produce greater statistical variability if the
traffic
> > > level
> > > > > > > is low. Higher volume gates have less variability from second
> to
> > > > > > > second, even though the total counts will of course be
> different.
> > > > > High
> > > > > > > volume gates have lower statistical error than low volume
gates,
> > > in
> > > > > > > other words.
> > > > > > >
> > > > > > > Best,
> > > > > > > Noah
> > > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Alan Penn
> > > > > > > Sent: 09 March 2005 12:38
> > > > > > > To: [log in to unmask]
> > > > > > > Subject: Re: Publically available standard test cases
> > > > > > >
> > > > > > >
> > > > > > > Absolutely right Rui - all observers should have a watch.
> > > > > > >
> > > > > > > Alan
> > > > > > >
> > > > > > > Rui said:
> > > > > > > >
> > > > > > > > I was one of the people who did these 'observations'.
> > > > > > > >
> > > > > > > > We were told nothing on methodology -how do you count people
> > > over
> > > 5
> > > > > > > > minutes?
> > > > > > > >
> > > > > > > >
> > > > > > > > My counts had an error of about 18%, depending on whether
you
> > > count
> > > > > > > > for 5 minutes or 5 min 20 s (10 secs at beg & 10 sec at
end).
> > > You
> > > > > can
> > > > > > > > fit almost anything you like to data with such high errors.
> > > > > > > >
> > > > > > > > Rui
> > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: [log in to unmask]
> > > > > [mailto:[log in to unmask]]
> > > > > > >
> > > > > > > > > On Behalf Of Nick Dalton
> > > > > > > > > Sent: 09 March 2005 11:04
> > > > > > > > > To: [log in to unmask]
> > > > > > > > > Subject: Re: Publically available standard test cases
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Don't forget the open observation exercise I held at the
> last
> > > > > space
> > > > > > > > > syntax conference.
> > > > > > > > >
> > > > > > > > > You can pick up the observation results at.
> > > > > > > > > http://www.thepurehands.org/massObs/
> > > > > > > > >
> > > > > > > > > more standard test sights and more standard observation
> > > > > information
> > > > > > > > would
> > > > > > > > be
> > > > > > > > > very useful.
> > > > > > > > >
> > > > > > > > > sheep
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > >For the Gassin maps on the VR website, I have actually
> spent
> > > a
> > > > > > > > > >couple
> > > > > > > > of
> > > > > > > > > >minutes to ask Julienne Hanson (who drew the maps) and
CUP
> > > (who
> > > > > > > > > >published them) for permission to publish the digitised
> > > diagrams.
> > > > > > > > > >Both were happy for the maps to remain up for academic
> > > purposes.
> > > > > > > > > >
> > > > > > > > > >I hope this serves to encourage the use of a standard set
> of
> > > test
> > > > > > > > > >cases for space syntax. However, I would still like to
see
> > > some
> > > > > > > > > >observation data made available. For example, within the
> > > > > > > > > >artificial intelligence community, the Anderson (1935)
iris
> > > data
> > > > > > > > > >has become a standard that is freely distributed to test
> > > > > > > > > >classification algorithms.
> > > > > > > > > >
> > > > > > > > > >Alasdair
> > > > > > > > > >
> > > > > > > > > >Rui Carvalho wrote:
> > > > > > > > > >
> > > > > > > > > >>On Thu, 3 Mar 2005 11:15:53 +0000, Alasdair Turner
> > > > > > > > <[log in to unmask]>
> > > > > > > > > >>wrote:
> > > > > > > > > >>
> > > > > > > > > >>>On vector maps: the maps on
> > > > > > > > > >>>http://www.vr.ucl.ac.uk/research/axial
> > > > > > > > are
> > > > > > > > > >>>high definition vectorised versions of the maps in the
> > > Social
> > > > > > > > > >>>Logic
> > > > > > > > of
> > > > > > > > > >>>Space. For Rui -- I am not sure whether these are
> supposed
> > > to
> > > > > be
> > > > > > > > open
> > > > > > > > > >>>access or not given the copyright of Social Logic of
> Space
> > > > > rests
> > > > > > > > > >>>with CUP. (Also, sorry Bin, they don't include fig
25.)
> > > > > > > > > >>>
> > > > > > > > > >>
> > > > > > > > > >>
> > > > > > > > > >>Well, of course the copyright of those images rests with
> > > CUP.
> > > > > > > > > >>Strictly speaking, it seems that the VR centre is
> violating
> > > > > CUP's
> > > > > > > > > >>copyright by not stating that clearly -just joking!
> > > > > > > > > >>
> > > > > > > > > >>My point is that it is your job to negotiate with CUP to
> > > make
> > > > > > > > > >>these
> > > > > > > > images
> > > > > > > > > >>open access. The readers should be spared the red tape.
> > > > > > > > > >>
> > > > > > > > > >>Rui
> > > > > > > > > >>
> > > > > > > > > >>
> > > > > > > > > >>>Alasdair
> > > > > > > > > >>>
> > > > > > > > > >>
> > > > > > > > > >>
> > > > > > > > > >>
> > > > > > > > > >
> > > > > > > > > >--
> > > > > > > > > >Alasdair Turner
> > > > > > > > > >Lecturer in Architectural Computing
> > > > > > > > > >Bartlett School of Graduate Studies
> > > > > > > > > >UCL Gower Street LONDON WC1E 6BT
> > > > > > > > > >
> > > > > > > > > >Course Director: MSc Virtual Environments
> > > > > > > > > >MSc Adaptive Architecture and Computation
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