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.

The web page “How did you contribute to OpenStreetMap?” (HDYC) provides individual detailed information about project members. Some time ago, the page has been revised, that member profiles can only be accessed, when users logged in with their OpenStreetMap (OSM) user account. This feature has been implemented, after a long and important discussion about “protecting user privacy in the OSM project”. The complete German discussion can be found here. However, I don’t want to continue the discussion here. I still support that any information, which are available about contributors, should not be hidden in project data dumps, APIs or on webpages. In my opinion, information such as contributor names or ids and modification timestamps are essential for doing quality analysis and assessments to protect the project against e.g. vandalism or unintended map edits.

The latest version of the OpenStreetMap editor iD has a new feature: “Allow user to request feedback when saving“. This idea has been mentioned in a diary post by Joost Schouppe about “Building local mapping communities” (at that time: “#pleasereview”) in 2016. The blog post also contains some other additional and good thoughts, definitely worth reading.

However, based on the newly implemented feature, any contributor can flag her/his changeset and ask for feedback. Now it’s your turn! How can you find and support those OSM’ers?

• Step 1: Based on the “Find Suspicious OpenStreetMap Changesets” page you can search for flagged changesets, e.g. limited to your country only: Germany or UK.
• Step 2: Leave a changeset comment where you e.g. welcome the contributor and (if necessary) give her/him some feedback about the map changes. You could also add some additional information, such as links to wiki pages of tags (map features), good mapping practices, the OSM forum, OSM help or mailing lists. Based on the changeset comment other contributors can see that the original contributor of this changeset already has been provided with some feedback.

As mentioned in my previous blog post about detecting vandalism in OpenStreetMap (OSM) edits, it’s highly recommended that contributors use public changeset discussions when contacting other mappers regarding their edits. This feature was introduced at the end of 2014 and is used widely by contributors today. Each and every comment is listed publicly and every contributor can read the communication and, if necessary, add further comments or thoughts. In most cases where questions about a specific map edit come up, it is desirable that contributors take this route of communication instead of private messaging each other.

For my presentation at the German FOSSGIS & OpenStreetMap conference I created several statistics about the aforementioned changeset discussion feature. For this blog post I reran all analyses and created some new charts and statistics. Let’s start with the first image (above): It shows the number of commented or discussed changesets per month since its introduction. The peak in January, 2017 is based on a revert with several thousands of changesets.