David Earl wrote: > I've said before and I'll say again: we need a way of > asserting "this area is complete" (for one or more > definitions of completeness).
Andy Robinson (blackadder) wrote: > The only way that we are going to individually or > collectively state the completeness of a specific area > is to carry out a verification process. It doesn't have > to be done by third parties or even different contributors > but it does need to be done by someone. > We need a simple tag to display verification, perhaps > the username and a date, say verification=blackadder_20080111 > or similar. Martin Trautmann wrote: > Is OSM that far that we need verification and quality ensurance? > We are still far from completeness, which might be a primary goal. I have started a new thread with a measure for completeness in the title because this is an important topic for OSM. But the response to the recent posts quoted above, and my raising of it last July, has been only luke-warm. I wonder whether this is because "completeness" is associated in people's minds too closely with verification. As Andy has describes it in the (incomplete) quote above, verification involves individual accountability - "I personally accept responsibility for the accuracy of this data". I don't think this is suitable for OSM at the moment; it may be necessary in the future if and when OSM becomes a serious alternative to commercial suppliers - but not yet. I, and probably others, are eager to make their contributions of as high quality as possible, but are wary about making a public and personal commitment to their accuracy. As is the case for all other mapping information, an assertion of completeness should only imply the best endeavours of the contributor, not a guarantee of 100% correctness. If you have ridden round a housing estate systematically and collected all the required information, you can reasonably say the area covered is complete. With this understanding, completeness would become part of routine mapping. It would encourage a systematic approach and the collection of any missed information. A possible detailed approach is as follows. A completeness boundary would be modelled on coastline: it would enclose an area, but would consist of many (ordinary) ways, with the completed area on the right. They would be tagged with one (or possibly more) definitions of completeness like "major roads", "public roads", "public paths", which would be defined on a wiki page. Boundary ways would be moved or added on a day-to-day basis by anybody with local knowledge. An area might even have holes in it. Somebody would provide an overview map showing completed areas, and its animation would feature in most presentations on OSM. OSM really needs a measure for local completeness to demonstrate its progress externally. I hope enough people can be roused to discuss, and hopefully agree, the principles, before deciding on an implementation. Chris _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk