[MapRoulette] Request for comments: Liking and Flagging challenges

Hi all. I have opened two tickets on the MapRoulette issue tracker to cover two new features that are closely related. The first is the ability to “like” a Challenge, and the second is to “Flag” a challenge. Liking should be self-explanatory. Flagging is a way to signal that you think the challenge is confusing / causing bad edits in OSM.

This short blog post on the MapRoulette blog gives some background and links to the issues. If you have opinions or suggestions please discuss on the issue pages. Thanks.


The maproulette process is still fundamentally broken.

Whilst trying to track down some data that had “disappeared” from OSM (someone changed it from what appears to be an accepted, documented value to something else) I tried to find the challenge author in order to find out where (or if) they discussed it with the wider OSM community, as would be required of a “change tag X to tag Y” mechanical edit, which is what this “challenge” is. There appears to be no way to do this.

I was only able to see the challenge after logging in. That gets me to https://maproulette.org/browse/challenges/24298, but I can’t see any way there to find out which user is responsible for creating the challenge. Clicking on a bit of grey on the screen that doesn’t look like a link, but is, gets me to https://maproulette.org/browse/projects/47143, but i cannot see which challenges were even part of the project because “No challenges remaining in project”.

I do not want to “get in touch” via the link on MapRoulette . My experience with maproulette challenge authors (and HOT tasking manager task authors) is that any message would just disappear into the void and be ignored.

I do not want to “flag” a challenge within maproulette for the same reason - issues I and other people have raised directly @mvexel seem to have just been ignored.

@mvexel Please reply here with the author of https://maproulette.org/browse/challenges/24298 so that I can contact them about that challenge, and also a list of the other challenges in https://maproulette.org/browse/projects/47143.

Edit: spelling.


Thanks for the feedback. We’re actually addressing some of the issues you raise:

  1. The log-in requirement to see the Challenge browse page is a bug that we’re working on.
  2. Soon, adding a comment in the Challenge page will trigger an email to the Challenge owner, making the comments made more visible to the challenge owner. We’re considering making challenges un-discoverable if the Challenge author does not respond within a certain amount of time.

Some possible new improvement opportunities I picked up from your comments:

  1. Make it easier to discover the OSM username for the Challenge owner on the Browse page. Filed as a new issue on Github.
  2. The fact that a Project page linked to from a Challenge page can be empty is confusing. New issue here.

The best way to suggest ideas like this is to open an issue on Github. I’m reading everything related to MapRoulette here as well, but it’s hard for me alone to keep up with all feedback coming in and turn it into issues and, eventually, improvements.


Thanks Martijn. To be clear, I’m not really trying to “suggest ideas” here, what I asked was:

You posited that the MapRoulette process is “fundamentally broken” and were pointing out a few pain points, which I took as suggestions. Like how you can’t easily see who created a challenge from the browse page.

zorglubu created the challenge you pointed to. Other challenges in this project.

Thanks - good to know that that API format https://maproulette.org/api/v2/project/47143/challenges works.

Yea, most everything in MapRoulette can be read-accessed with the API. It’s just building UX around it that’s sometimes hard & more time consuming.


Actually one more question - is there an RSS feed of “new challenges”?

Had it been immediately visible when it was added, a challenge whose entire description was “Replace diplomatic=high_commission with diplomatic=embassy + embassy=high_commission” (an obvious mechanical edit) could have been nipped in the bud.

Not currently. Interesting idea though.

1 Like

Ticket for RSS feed opened, RSS feed for newly created discoverable challenges · Issue #1904 · maproulette/maproulette3 · GitHub Not currently scoped however.


An update, it is now possible to Flag (or “report”, still not sure what the best term is) challenges. A short blog post by the devs who implemented this is here.


That seems to have been closed without a fix actually happening?

What I wrote a few months ago still largely seems to be true - the UI is still very limited. There are the API links above of course, which should allow people to download the revevant data before analysing it manually. The bug that was open for this seems to have been closed without the issue being fixed though, or maybe it;s just not live yet?

Is there any documentation of what APIs there are?

The API documentation can be found here:



If that is what passes for documentation these days then I am William Shakespeare :slight_smile:

What seems to be missing is the hiearchy of metadata. For people not familiar, could you briefly describe the Challenges, the projects, how they are related. Is there an instruction to list all challenges, all projects, plus geolocation and a brief description of these ?

1 Like

All the conceptual stuff is explained in the end user documentation? Documentation | MapRoulette Docs. In my opinion it makes sense to use MapRoulette first before trying to access the API? There you will quickly discover the hierarchy of projects › challenges › tasks.

I’m using the API because it was suggested by the Maproulette author above. What I’d like to be able to do is to download a list of “challenges” that form part of a “project”, and then download a list of changesets that have been performed as a result of each challenge. I can get changeset data and metadata from the OSM API; but I don’t see a documented way of getting a list of changesets (without going through the code, of course).

For context, I’m a member of the Data Working Group, and we occasionally get reports of problematic challenges**. The Maproulette UI’s openness to outsiders is somewhat limited (see above in this thread), but the API appears that it might be an easier way to get at that data.

** we have 4 tickets open at the moment, of varying ages.


Is this feature handled by someone? No generated issue has been closed yet since February 3 (the three closed ones are tests).

MapRoulette and OSM are not integrated at this point. A user looks at a task in MapRoulette and locks it. They do the OSM edit normally in an editor and upload the changeset. OSM and the changeset don’t “know” anything about MapRoulette. There’s a suggested changeset comment, but users are of course free to change it – most don’t. And then you go back to MapRoulette to mark the task as completed. You could also submit several changesets for one task. Or none at all if you fixed the task already yesterday.

So there’s no direct way to find the changesets that came out of a challenge.

In the past what I’ve done is to get the contributors to a challenge and the days they were active. Then fetch all changesets of these users on the days they were active. And finally filter the changeset comments for the hashtags or URL MapRoulette proposes to put in the comment.

It’s a bit cumbersome to work with two disconnected APIs, but for me it worked well enough.

Here I created some contributor stats for a finished challenge, and evaluated the changesets this way: Ungemappte Wohngebiete in Deutschland anhand Zensus - #256 by hfs

Here’s the code I used to fetch the status of all tasks of all challenges in a project, using the Python MapRoulette Client library: landuse_without_buildings/13_challenge_status.py at master · hfs/landuse_without_buildings · GitHub

And here’s the code to correlate that with changesets of the contributors: landuse_without_buildings/14_mapper_stats.ipynb at master · hfs/landuse_without_buildings · GitHub

Maybe that helps?