Power editing with OverpassTurbo and Level0

Posted by joost schouppe on 10 June 2015 in English (English)

Recently, I came across some villages in Bolivia which have "aldea" for a name. Upon closer inspection, I discovered there were over 600 in the country. The size of the problem is easy to find with Overpass Turbo. Just tell the wizard to search for name="aldea" and it will do everything you want. Thanks to the Argentine twitter feed, I knew that you can search for this in a whole country, as opposed to within a bounding box. Here's what the output looks like. I left some cases as a reference.

Obviously, the name tag is not for the description. These 'aldeas' were already properly classified as hamlet, village, etc, so there was no information in there. These were untouched nodes without a history. After brief consultation with the Bolivian community, I decided to go ahead.

Now, as a Potlach 2 mapper, I didn't know how to fix this in JOSM. I've opened JOSM maybe five times, and every time I shut the thing down after 15 minutes. I know.

I read some use cases for Level0 before, and this seemed to be one. It was much easier than I thought. After running the query, you can hit the "Export" button and choose Level0. This opens the Level0 editor. You still have to log in and allow the editor to access your account. Apart from that, I just copied the text to Notepad++ and did a Find and Replace for "name = aldea" to "fixme = needs a name". Hit save, and you just fixed 500 villages (max 500 objects per edit!).

Now I know, you shouldn't just mass edit these things and walk away. So I though why not create a Maproulette task to check these villages - maybe some of them had a duplicate node around with the name. After reading the simple guide to creating a Maproulette task, I changed my mind. But I did remember seeing a guide to taskfixing in Potlach. So I made a new query for the fixed villages. Didn't work when trying to load as a GPX, but worked a charm when I exported the query to GeoJSON format.

I already knew Overpass Turbo was a killer machine. I knew the beautiful maps you can build around these queries, like making an up to date map of the Belgian breweries in OSM. And now the combination with Level0 is another tool to turn people turned off by JOSM into power users.

And I didn't even need Help this time.

EDIT: I did get ahead of myself a bit: you really shouldn't do this before talking to the people who mapped these things. I'll do that now - it is an easy revert if in fact there is some very good reason for abusing the name tag on this scale.

Comment from Warin61 on 11 June 2015 at 04:03

Ummm you don't say that you contacted the person who did this... Nor that you checked that the name had not been changed from something more relevant...

Can one assume that you did this?

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Comment from joost schouppe on 11 June 2015 at 06:15

Hey Warin, I did check the history on some of these nodes. From what I can tell, it's remote mapping, not someone erasing real names. But in my enthousiasm I didn't think to stop and ask the mapper(s) who mapped the places like this. I wouldn't think twice to do that if I were stumbling upon them one by one, but I can see how that is different on this kind of scale. Sorry! I'll contact them now - this is really a simple edit, so a revert shouldn't be any problem. I edited the post above to warn people to do as you said.

Not that I can see any valid reason for the way to map it like it was. I understand the rules for situations where there could still be discussion about how to map things - I just didn't see this case as a possibly controversial one. And I did take some precautions, as you see above.

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Comment from Warin61 on 11 June 2015 at 10:46

I too cannot see a valid reason. I'd look forward to their explanation ... could be cultural? Or just an experiment that was not meant to be seen. They may not reply. In any case worth while to contact them .. so they know things are being done and they are being 'observed' at least in part.

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Comment from Vincent de Phily on 11 June 2015 at 11:12

Also, tags like "fixme=name missing" are pretty much useless, because that information is already there. Plenty of QA tools already point out nameless POIs/places, and querying the same via Overpass is also very easy.

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Comment from Polyglot on 18 June 2015 at 06:57

Hi Joost,

I wouldn't mind doing a few Hangout sessions with you to show you the wonders of JOSM and how it works. Once you get used to it, it's very unlikely you'd still be put off by the software. It's just that initial learning curve bump you have to overcome.

There are also many tutorial videos on Youtube, created both by myself and by other contributors.

Having said that, there probably is a use case for level0 as a "quick and dirty", hands-on editor.

With JOSM you could have additionally performed Search At that point you could change tags for all selected objects at once (like you did with Level0), or you could have Added nodes to a todo list, to review them and work on them one by one, which makes the 'mechanical edit' a bit less mechanical Switched on MapCSS rules to highlight village name nodes to compare with nearby ones Or enable filters to hide everything that's not relevant for the task at hand.


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Comment from dieterdreist on 18 June 2015 at 14:40

Your edit was clearly a mechanical edit and should have followed the mechanical edits guidelines, especially should have been discussed beforehand to see whether there might be some problems (e.g. maybe some of these places really have this name?). The problem I see with maproulette etc. for cases like these is that you do need local knowledge to judge on a name, the missing name problem is not very suitable for remote correction without knowing the object and context.

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Comment from joost schouppe on 18 June 2015 at 16:33

Dieter, I tried to contact the mapper in question two times now. No response. I think he speaks Russian, so maybe he just doesn't understand? I did talk to the local community before going ahead, and they were more than ok with it. I lived in Bolivia long enough to know that no village is called "Village" there. And if ever the user comes with a proper explanation, this is one easy edit to revert. So, yes, I should have waited a week or two before going ahead, but other than that, I really don't see a problem.

By the size and type of his edits (e.g. this and this, I think he's doing imports without mentioning the source. This has raised eyebrows before. Also note the lack of common node between rivers where they join - maybe an error when converting data?

As for the Maproulette or manual revision: I thought this might be useful, because I found a case where the residential area around the node had the name of the village, but not the node. But I checked quite a few of them manually, and didn't find any other cases. So no, a Maproulette task would not be useful to find the names. However, it might still be useful to add roads to these places. This is one area of the world where -a lot- of roads are still missing!

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