[OSM-talk] Mind the Gap - how to see where OSM is lacking

Jóhannes Birgir Jensson joi at betra.is
Sat Oct 26 16:53:06 UTC 2013


In the Wikipedia topic Christoph Hormann said

 >Although this is difficult to back up with numbers i have the impression
 >the gap between well mapped and badly mapped areas in Openstreetmap
 >is widening even though you would think it is much easier to improve a
 >badly mapped area than a well mapped one.

This is something that has been on my mind as I compare my two main 
areas of mapping. My home country of Iceland (mostly detailed and 
currently looking at imports from the national land registry, via proper 
channels) and Botswana, another sparsely populated country, one sorely 
lacking in data.

My first task was to find the 2011 Botswana Census and make sure all of 
the towns and villages there were on the map. Most of them weren't so I 
enlisted the aid of Wikipedia (the Italian one actually has the most 
detail!) to find their GPS co-ordinates. Then I started to draw roads 
and buildings in Bokspits, the southernmost village, and its 
surroundings. Soon I figured that this would not be the most efficient 
use of time, rather I should focus on at least connecting each of the 
town/villages to the road network. That is currently my focus and I 
created a MySQL table to make it easier to have an overview over which 
are connected to road network and which are yet to be connected.

Botswana was, and still is, pretty lacking in details outside of its 
largest cities. So it is a badly mapped area. Iceland is a well mapped 
area but still lacking details, so I created a taskboard in Trello to 
give us a to do list. This list shows on the leftmost column those town 
villages lacking imagery (Vantar loftmyndir), lacking buildings (Vantar 
byggingar), in progress (Í vinnslu) and finally completed (Búið), 
meaning roads and buildings have been mapped. URL: 
https://trello.com/b/dn0f5v5p

I started to set up a similar list for Botswana but soon found that 498 
towns spread over 7 such task boards was very unwieldy!

So the Icelandic OSM community, which formed Hliðskjálf, a society for 
free and open GIS data, last Thursday, decided to start to work on some 
sort of Quality Inspector. Currently all discussions about it are only 
available in Icelandic but once our ideas are better formed we will 
switch to English for wider discussion.

The basic idea is to be able to create automatically an overview of a 
locality within a region, listing for example number of emergency 
services within it, education facilities, roads, buildings etc. Then 
human input gives ratings for various things like how much of the road 
network is done, how many buildings, cycling and pedestrian network etc. 
It will probably require substantial work to set it up but once it is up 
and running it should make it easier to notice sore thumbs, areas 
completely or mostly lacking in data, wether on a global scale or a more 
local scale. Another idea is to run differentials on it every month or 
so, making it easier to notice if a place is suddenly shooting up in 
services or buildings or whatever metric, meaning a mapper is working on 
it, one we can perhaps support, and if needed, gently and tactfully help 
him/her improve his/her work.

We plan to run Iceland and Botswana into it for initial testing and 
hopefully, if it proves to work, to open it up for others to import 
their own areas.

As said, currently all we have on it is in Icelandic and it is still on 
the drawing board but we are working on prototyping and converting to 
English.


best wishes,
Jóhannes

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