[Numpy-discussion] Meta: help, devel and stackoverflow

Fernando Perez fperez.net at gmail.com
Thu Jun 28 17:57:24 EDT 2012

On Thu, Jun 28, 2012 at 2:07 PM, Matthew Brett <matthew.brett at gmail.com> wrote:
> I see that sympy, for example, has only one mailing list, and that
> works extremely well.  I'd be interested to hear from the Cython and
> IPython guys as to whether they feel the user / devel split has helped
> or hurt.  Ferando? Dag?

There's evidence that projects can work successfully in either mode
(single/dual lists), so I don't think this is a completely clear-cut
question with a 'right' and a 'wrong' answer.  What matters most is
finding for each project and community what works best, and I think
the main factor should be how truly disjoint are the topics and
typical threads of the two lists.

Before talking about IPython, we can consider Python itself, where
there's a very clear division between the general and dev lists, and
even the dev list has been recently split with a new 'ideas' list
where more exploratory threads can take place, so that -dev can remain
100% focused on active, concrete development work on the main Python
repo.  And that strong separation of lists (which python-dev enforces
strictly by calmly but firmly redirecting threads to other lists as
soon as they seem off-topic for the narrow python-dev focus), seems to
work pretty well for them.

As far as IPython, I personally do prefer the separated lists, and I
think it works quite well for us.  IPython is a project often used by
python beginners for simple learning of basic programming, and they
just want to know how to tab-complete or how to get plots to run in
non-blocking mode.  Our -dev list is relatively high-traffic and with
a weird mix of topics, given the rather eclectic nature of IPython: we
have qt discussions, parallel computing, low-level networking/zeromq,
javascript/web issues, protocol API threads, etc.  All that can be
overwhelming for novices (though obviously one hopes that novices
would gradually learn from that and become interested in being

I think this is how I'd summarize it:

- having two lists is friendlier to beginners, as it gives them an
environment in which to ask questions that they may feel more
comfortable in, because the level of the discussions tends to be not
as complex as what happens in a -dev list.

- but the cost it has is that it insulates users a bit more from the
development ideas, perhaps lowering the likelihood that they will
catch on to the development conversations and dig deeper into the

My cartoon view of it would be:

a. novice person | user list  || dev list

b. novice person || combined list

where the | bars indicate 'barriers': in (a), a novice has a low
barrier to become a good user, but a higher barrier to transfer into
developer.  With (b), there is no clear barrier to becoming a
developer, but it's more intimidating for new users to join.

I have heard (but I only have anecdotal evidence) of users saying that
they feel more comfortable asking questions in user-only lists because
of the level of the discussion, and that they can read all messages
and learn something without having to filter threads that are way over
their heads.

Long answer, I know... But in short, I'm happy having two lists for
IPython: I prefer to have the first transition (gaining active users)
to be the easiest to make, because I think once users have become
confident, the cost of digging deeper into development is actually
pretty low.

But I'm sure other projects can and have successfully made the opposite choice.



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