[R] Re: Number of R users

[Martin Maechler]

I have been asked again about the numbers of R users.
The following is part of my answer, probably of some interest to some.

    >> In preparing some notes, I'd like to give some
    >> approximate baseline estimate of how many people are
    >> using R nowdays.

of course a very interesting question.  It came up on R-help
in June 2000, with a small "heated" debate :
start at   ---> http://www.r-project.org/nocvs/mail/r-help/2000/1493.html
but first, read on.

    >> perhaps the size of the R-help list would be a decent
    >> starting point. Any chance you could give me the
    >> approximate number of users?

Well, as with practical statistics, at first it's trivial, but
if you start thinking it becomes quite "interesting"..
At the moment, 
o  R-help      has	2005 unique e-mail addresses subscribed
o  All R-lists have     2659 for "R-*" alone, i.e. w/o bioconductor
o  ALL R-lists have	3189 unique (all "R-*" lists + "bioconductor"
				     combined, then "uniqued") addresses,

But from the mailman logs, for R-help e.g., this noon,  
	 1023 got r-help directly
	  780 got r-help as digest
which leaves about 200 (~ 10%) who seem to have mail delivery
disabled for some reason {explicitly, by bouncing, delivery
not-disabled but not successful on first try, ..?..} 

Then I also guess (from the address) that some groups deliver
R-help to an `internal mailing list' ((something we pretty
strongly discourage, particularly since it complicates unsubscription)).

Now you should probably read the R-help discussion thread from
two years ago (URL above). Quite interesting.
People's guesses wildly varied then from about 10'000 to 400'000 --
based on about the third of mailing list subscribers.
The multiplication factor `f' in    R_users = f * R-help_readers
was conservatively estimated in the range of 10-20 (rather the latter).
This would lead to a guess of about 50'000 users (with a wildly estimated
[logarithmic] standard error of "factor 2").  I think most would
agree that this would *not* count students who only use R during
their classes. 

(Please before you comment on this, do read the "June 2000" thread ..)

-- 
Martin Maechler <maechler at stat.math.ethz.ch>	http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum  LEO C16	Leonhardstr. 27
ETH (Federal Inst. Technology)	8092 Zurich	SWITZERLAND
phone: x-41-1-632-3408		fax: ...-1228			<><