These are very interesting figures, but only for EN Wikipedia. I
concur with Gerard in that we also need to compare figures with other
languages, specially outside the group of large Wikipedias.
The generational relay is a well-known effect in open communities
(for instance, it has also been studied in open source projects).
However, the size of the community and the size of the group of core
contributions does matter. Losing 3 persons in a group of ~500 can be
probably assumed by the rest of the group, whereas losing the same 3
in a group of 20 is a very different story.
Furthermore, the duration of idle periods (between two consecutive
edits) is also important. I am conducting a systematic analysis of
this factor (that is, no sampling), against other relevant metrics
(lifetime, number of edits or date of the first edit). It is not
unfrequent for "casual editors" (< 100 edits) to have idle periods of
more than 2 or even more than 4 years. But this idle period is
usually
shorter for core editors (longest periods usually between 3-6
months).
I mention this because, according to one of the comments on
http://en.wikipedia.org/wiki/Wikipedia_talk:List_of_Wikipedians_by_number_of_edits#Suggest_explaining_what_it_means_to_have_a_user_name_in_black_.2Flinkless
the meaning of "inactive" top editors in this list is (verbatim):
"editors with more than 30 days since the last edit". I find this
definition of "inactive editor" at least questionable under the light
of these results about idle periods.
The first conclusion is that editors with over 35K edits are much
less likely to
leave, increasingly unlikely as the # of edits goes up. This is
clearly
statistically significant.
The second conclusion is that there is major loss of editors with
about 20K
edits. I am not sure how statistically significant this is.
Since the table is clustered by rank, rather than by number of edits,
I would report instead about "top-2000" or "top-2500", since absolute
figures in the table are actually meaningful just relative to the
performance of other editors. I would also try to normalize edits by
lifetime, to compensate the fact that editors with longer lifetime
had
better chances to make more edits (which may hide fast-raising
trends). But the, admittedly, that would be a different table for a
different purpose...
I obviously did not try to correlate this with the lifetime, but if
we take 10K
edits per year as an example, 2 years would be the most probable
lifetime.
Richard Rohde reported slightly higher numbers.
So, yes, indeed, the editors leave after a couple of years, and they
do not get
replaced.
In any case, I believe this is the key question to answer. Trying to
characterize editors who stopped their activity, either temporarily
or
permanently, is only one half of the picture. The other half is
learning what was the path that core editors followed till they got
there, and why now we have fewer people following that path.
Why is this interesting for the whole Wikipedia community? Just for
the fun of counting edits? For the sake of competition? No. It is
important because very active editors are supposed to have much more
experience in the project, and that experience, that knowledge about
the editing process, about how to interact with other community
members, and how to build valuable content is a crucial asset for
Wikipedia. Thus, I think that the focus should also include senior
members outside the list of top editors, but with a long-time
experience (e.g. +5 years). Let me recall that the vast majority of
authors who have participated in FAs had a total lifetime of more
than
3 years (+1,000 days) in Wikipedia, for all big languages (note:
also
for most of the middle-size Wikipedias).
Last, but not least, there is another important connection with
maintenance activity. Editors with special accounts (e.g. sysops) may
become idle for several days in article editing, but they continue to
perform administrative duties systematically. As a result, the trends
in the number of new admins and RFAs, and number of administrative
changes performed over time should also complement this picture
(since
many, many admins were not among the most prolific editors when they
were appointed).
Best,
Felipe.
