Last year I wrote two blog posts about the OpenStreetMap (OSM) feature that allows commenting on contributor map changes within a changeset. The first blog post showed some general descriptive statistics about the number of created changeset discussions, affected countries, the origin of the commenting contributors or their mapping reputation. The second post described a newly introduced feature, where contributors can flag their changeset so that their map edits can be reviewed. This blog post will follow up on this topic and conducts some similar but updated research.

The first chart shows the number of created comments (discussed changesets) and the contributors involved over the last 15 months. The number of created comments and discussed changesets fluctuates over time, whereas the number of contributors who take part in changeset discussions stays consistent at around 1,500 per month. Around 3,200 contributors received a comment on at least one changeset’s map edits a month.

After publishing the aforementioned blog post, people were asking for some numbers that show the commented changeset grouped by the editing application that was utilized. The results show that these numbers stayed more or less the same with 2/3 of all commented changesets (almost 160,000) being edited by the iD editor. This is not very surprising since this particular editor is used by many OSM beginners during first edits. It’s also interesting to see whether the changeset author responded (also grouped by the OSM editor that was used). Overall only around 32,000 contributors responded to their changeset comment. You can find some additional charts about the comments per discussed changeset in the previous blog post. Again, the majority (around 71%) of the changeset discussions contain one comment only.

Since last August, contributors can mark their changeset with a flag for “review_requested”. After a few months now I think it’s time for a first look at the numbers. The following charts display the number of requested reviews by contributors and their marked changesets. First of all, almost each month around 7,000 contributors asked for one review minimum. Overall almost 36,000 changesets have been marked for review each month. If we take a close look and filter changesets by hashtags, we can see that sometimes large numbers of the changesets are contributed by #HOTOSM or #MissingMaps members.

The following diagram shows probably the most disappointing results: The number of requested reviews that actually have been reviewed in the end. No matter if the changeset has the #HOTOSM or #MissingMaps tags or not, the relative value of reviewed changesets lies only between 6 and 18%. To be honest, I’m also a bit surprised that only a few of #HOTOSM or #MissingMaps changesets have been reviewed so far.

So, what do you think? Do you review contributions without commenting on the changesets? Do we need more attention here or is it just boring to look after changesets which are marked for review? I think it’s obvious, that we need more contributors who review map changes or least “documenting” their work. But can we handle this? Or do we need better tools?

Thanks to maɪˈæmɪ Dennis.