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RE: Scheduling unpleasantness

2008-03-24 16:11:29


        See below... :-)

Eric Gray
Principal Engineer

-----Original Message-----
From: Brian Dickson [mailto:briand(_at_)ca(_dot_)afilias(_dot_)info] 
Sent: Monday, March 24, 2008 6:16 PM
To: Eric Gray
Cc: Iljitsch van Beijnum; IETF Discussion
Subject: Re: Scheduling unpleasantness
Importance: High

Eric Gray wrote:

... [SNIP] ...

    This sort of scheduling problem is very well known
to be NP hard and trying to meet the scheduling conflict 
matrix for 1500 to 2500 people would make the "N" large.

Universities have been doing this successfully for class 
scheduling for many years with great success. I would not
necessarily classify it as "hard".

Universities are not doing "this sort of scheduling", not
even close.

Do you suppose we could have everyone register for all of
the meetings they need to attend and then we could have the
same meeting - perhaps with a different WG chair - several
times during the week in order accomodate those who are 

If we're interested, but have a conflict, can we pick some
other subject for the time-slot and attend the meeting we
really meant to go to at the next IETF?  Surely it will be 
essentially the same meeting, right?

o   you can't reliably expect people to differentiate
    what they "want" from what they "need" when asking
    for this kind of input;

There are two key constituents, which it cannot be denied meet the 
"must" category. WG chairs, and presenters.

Presenters do not have to be at the entire meeting.  It can 
be embarrassing if your presentation goes off on a tangent 
that was earlier forbidden in the same meeting, for instance,
but it is not fatal.  Having a WG chair come and go during 
the meeting might be a bit more disruptive.

Also, the fact that you are neither a WG chair or a presenter
does not mean you do not need to be at a meeting for other

I was faced with pre-conference scheduling conflicts for two 
presentations.  They thankfully ended up not conflicting, 
because the WG's were both split in two, and my presentation 
schedule was split across the two time slots.

Yes, things like this can be worked out without complicating
the meeting schedule.  The complexities come into it when you
need to be at the entire meeting.

However, both halves of both WGs were scheduled to be 
simultaneous - WG-A1 and WG-B1 together, and WG-A2 and WG-B2 

And that's been happening a lot the past several meetings, 
which is why I said that this meeting might not have been
the worst for everybody.

I would say some close attention could be paid to the subject 
matter, and to determine that there is in fact a natural 
overlap between these groups in particular:


(As they all have to do with global routing, advances in
routing protocols, and new routing technologies, each with
unavoidable overlap in subject matter and participants.)

Yes, and after doing this for several meetings in a row and
finding out that the WG chairs cancelled the IDR meeting (for
at least two meetings in a row), maybe you stop spending your
impossible-to-replace time worrying about that.

    One approach to address at least these issues is to
consider (perhaps as an experiment) adding a check-list of
meetings people would like to attend to the registration

There is certainly a very reliable basis for tracking 
"interest", and in particular "co-interest indices",
based on the "blue sheets".

Except that it is (I believe) well known that the blue 
sheets are used almost exclusively to determine what size
rooms to reserve for the next meeting - which really only
requires counting the number of filled in lines and pages.

This is an interest indication, but only for how many.

I seriously doubt if anyone is transcribing these sheets 
into electronic format where they could be used for this
purpose.  Nor would it be trivial to do so given the poor
hand-writing most of us have after all these years doing
almost everything on a computer.

Try reading a few of the entries on the blue sheet next
time you scribble in your name and email address.

Here's how to do it:
Track across multiple meetings, using anonymized identifiers,
to show which WGs have significant overlap.

This is not a bad idea, and could probably be done with the
information already available - i.e. - wireless card MAC
addresses and associations with specific access points at
specific times during the day.

Similarly, break up into several "pools", those with minimal 

But this approach has the same drawback previously pointed
out with asking those of us who are already attending IETF
meetings, where we would like future meetings to be held -
i.e. - the statistic is poisoned by the forced choice that
people have been obliged to make.  Clearly the fact that 
you can't be in two places at one time is not an indicator
that you did not want to be.

Those should ideally form a set of N pools, where each pool 
needs to be coordinated, but where no coordination inter-pool 
is needed. The pools correspond to "tracks", in track-oriented

The first step is to acknowledge that there is a problem, and 
to make a commitment to addressing the problem in a systematic

Yeah, these are first steps.  Of course, if you read all the
way through my earlier mail, you would have picked up on the 
possibility that just having a fixed schedule is a simpler
solution.  That would force those of us who are constantly
seeing conflict to seek a more or less permanent answer to
the problem - like getting someone else in your company (or 
organization) to attend some of the conflicting meetings.

Instead, we now have other consideration - like who gets to
have their meetings on Monday and who has to have them on
Friday? Or why can't we bunch up certain meetings because
some of the people can't be at the IETF meeting for the 
whole week?

So, the problem has been bad now for several meetings. I
see no reason to suppose that it was worse this time from 
everyone's perspective.

Brian Dickson

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