While playing around with the changeset data I noticed an interesting pattern. There were some users who had made a lot of contributions to the map, who were nowhere to be seen. A lot of the talk in the community has been on attracting new mappers, but if we’re losing existing mappers that is surely a problem, no?

Wondering if this was a big problem, I decided to dig in. Here is what I found – it doesnt seem to be a HUGE problem at the very top, but there are many mappers who make 10 or 100 changesets that never come back. Note that this is only using data from the USA at the moment.

First thing to notice is the blue line – these are how many users there are for a minimum number of changesets. 44k users have more than zero changesets, 25k have more than one changeset, 100k have more than 5 changesets and so on. There are only about 273 who have more than 1000 changesets, and I’ve done my best to get rid of imports so these are likely to be real people, but Im sure a few of these include imports.

Now, how many of these users seem to be lost from OSM? The Orange, Yello and Green bars plot number of users who have not made a single edit within the US in since 2012, 2011 and 2010 respectively. So, for example, looking at the extreme right, of the 273 users who made at least 1000 changesets, 22 have not been seen since 2012, 12 since 2011 and 4 since 2010. The problem is a little bit more acute if you looked at those who made at least 500 changesets. Of this group, about 50 have not been seen since 2012.

Who are these users? And why did we lose them? Was it due to contributor terms or is it just bots which are no longer being deployed?

Here is the list of the top missing mappers that I could find in my data, heavy mapper that have not been seen since 2012! Chime in, in the comments if you have any theories about where these lost souls might be and what we can do to bring them back!

Here at the top 10 users who have at least 500 changesets and have not been since since 2012:

Click here to check out the full list!