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> From: Peter Miller <[email protected]> > To: Sam Larsen <[email protected]> > Cc: [email protected] > Sent: Wed, 2 June, 2010 18:00:47 > Subject: Re: [Talk-GB] >- Map layer with OS Locator comparison from ITO > > ... >> >> We're now able to get a > lot of data for free from OS, I don't think it's unreasonable to report the > odd > error back to them so they can improve their map. >> > > > +1 >+1 >Just to say that I was in discussion with the research guys > at the OS about this last week and the status reports which we hope to have > online next week will include a section of 'not:name's for each district > which > they have expressed interest in reviewing. The only small issue could be over > licencing, however I don't believe that they would ever want to act on a > report > in OSM without checking it first on the ground so it will purely be treated > as a > clue for their purposes. Peter, Having used the data in a number of vastly different areas in terms of completion, i have noticed that as a measure of completeness there are a few flaws. I have done name updates in remote Scotland & Wales where the OS Locator missing names tiles provide an incredibly valuable resource - mapping to the same extent as a huge number of nonamed roads. However, when attempting to get Cambridgeshire up to the top of the list for this measure of completion, i have noticed a large amount of really tricky & difficult to diagnose OS Locator noname extents. In areas where there has been a huge amount of pedal power mapping by some very enthusiastic mappers in the Fens north of Cambridge, the data in OSM here is generally of a very high quality, for this reason i would dispute many of the OS Locator missing name polygons. I would assume that a number of these are down to the 'historical' nature of OS data & place names. There are a number of local names for stretches of A & B roads, which i would think are probably not signposted or have not even used in the locality for a long time - these may be covered by historical name tag (which i think does exist in places). For that reason i would be hesitant to put too much faith in the level of accuracy using this measure when completeness becomes something like 90 - 95%. I still think that for the majority of places which have huge swathes of noname roads we have a very useful resource here when used with a bit of common sense and I think you have provided a valuable resource/workflow for those who are always on the lookout for measures of OSM completeness (in the UK). Another point - has anyone made moves to compare the data in the other direction i.e. comparing OSM roads & names with OS Locator - i have come across a number of 'new villages' (new roads within the last year or two) which i would assume are not in the OS Locator dataset. I guess this ties in with the feeding back of data to the OS - maybe they should run this using their budget to help guide their surveyors. Sam _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb
