----- Original Message ----
> From: Peter Miller <peter.mil...@itoworld.com>
> To: Sam Larsen <samlars...@yahoo.co.uk>
> Cc: talk-gb@openstreetmap.org
> 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
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