* How accurate is the data already in OSM? Interesting question Rob, as of today there's approximately 200,000 ways or nodes tagged with postcodes in OSM, this is made up of about 29,000 unique postcodes. Those numbers are not 100% accurate as my bounding box for getting the data overlaps a bit with France and Ireland. I've removed the obvious French postcodes (5 digits) there might be a few I missed although I'm pretty sure the extras don't skew the numbers too much.
I've compared the unique values from that list with the ONS dataset (excluding terminated postcodes) and come up with the list linked below [1] There's 1119 unique invalid postcodes, which of of course doesn't account for ways or nodes that are incorrectly tagged with a valid postcode but is a useful stat nonetheless. It should also be relatively easy to get those cleaned up I would think. Couple of notes about the data, there are a few postcodes that look like they are valid (e.g. BR3 1AZ, WC2H 9BD) but they have in fact got some invalid characters at the end that are not visible so that's why they are listed. It also includes postcodes in lowercase as well since it breaks from the convention of uppercase postcodes, you could argue that they should be in or out, but it was easier to leave them in. [1] https://docs.google.com/file/d/0B0viaV_xKHyCNmJDY1A1X092Zkk/edit?usp=sharing On 28 February 2013 23:44, Rob Nickerson <rob.j.nicker...@gmail.com> wrote: > Interestingly out of the 95 you also identified 2 postcodes that are > incorrect in OSM... raising the obvious questions: > > * How accurate is the data already in OSM? > * Should imports be compared to 100% accuracy or a more realistic measure > of OSM accuracy? > > Rob > > _______________________________________________ > Talk-GB mailing list > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb > >
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