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<div><br></div><div><br></div><div><br></div><div>Aug 6, 2021, 13:26 by colin.smale@xs4all.nl:<br></div><blockquote class="tutanota_quote" style="border-left: 1px solid #93A3B8; padding-left: 10px; margin-left: 5px;"><blockquote type="cite"><div>On 08/06/2021 12:20 PM Mateusz Konieczny via Talk-GB <talk-gb@openstreetmap.org> wrote:<br></div><div>Aug 6, 2021, 12:13 by colin.smale@xs4all.nl: <br></div><blockquote><blockquote><div>On 08/06/2021 11:23 AM David Woolley <forums@david-woolley.me.uk> wrote: <br></div><div><br></div><div><br></div><div>On 06/08/2021 06:57, Jay Turner wrote: <br></div><div>> Perhaps "ref:signed=poorly"? <br></div><div>> <br></div><div><br></div><div>That's subjective and OSM doesn't collect subjective information. <br></div></blockquote><div><br></div><div>Ahem... There are plenty of examples of (partially) subjective information in OSM. Tracktype and smoothness for example. Even highway=* gives rise to discussion from time to time, as one mapper's judgement differs from another mapper's. Only by reference to an authoritative source can all elements of personal judgement be eliminated from the equation. <br></div></blockquote><div dir="auto">And even then we would run into problems as soon as there is more than one <br></div><div dir="auto">"authoritative source". <br></div></blockquote><div><br></div><div class="">There cannot be more than one "authoritative source" by definition.<br></div><div class=""><br></div><div class="">There can be indirectly authoritative sources, which are individually derived from the authoritative source and can potentially disagree with each other, as a consequence of a mistake or temporal considerations (update date/frequency etc). Such apparent conflicts can be resolved by reference to the authoritative source itself.<br></div></blockquote><div dir="auto">With strict definition it turns out that most of what would be considered "authoritative source"<br></div><div dir="auto">actually is not.<br></div><div dir="auto"><br></div><div dir="auto">UK has much better governance than average and is much richer than average, so maybe it<br></div><div dir="auto">is quite rare to run into such issues. But it my experience it is common that supposedly<br></div><div dir="auto">"authoritative source" is often mismatching with itself, reality, other supposedly equivalent<br></div><div dir="auto">"authoritative source".<br></div><div dir="auto"><br></div><div dir="auto">And there is often conflict what actually is "authoritative source".<br></div><div dir="auto"><br></div><div dir="auto">Strict following of authoritative sources would result in plenty of misalignment,<br></div><div dir="auto">invalid data, ridiculous data etc.<br></div><div dir="auto"><br></div><div dir="auto">Actual example: some years ago firefighters in Poland ended using OSM data as source<br></div><div dir="auto">as official authoritative source was<br></div><div dir="auto"> (a) unavailable to them - AFAIK it improved since then<br></div><div dir="auto"> (b) different administrative units had own databases, with roads on border between<br></div><div dir="auto"> them mismatching location. In other words, authoritative sources disagreed<br></div><div dir="auto"> where intersection of road and voiwodeship border is located - such as<br></div><div dir="auto"> <a href="https://www.openstreetmap.org/?mlat=50.32434&mlon=20.29192#map=19/50.32434/20.29192">https://www.openstreetmap.org/?mlat=50.32434&mlon=20.29192#map=19/50.32434/20.29192</a><br></div> </body>
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