Andy Allan [mailto:[EMAIL PROTECTED] wrote: >Sent: 12 May 2008 10:52 PM >To: David Earl >Cc: Andy Robinson (blackadder-lists); talk@openstreetmap.org >Subject: Re: [OSM-talk] [OSM-dev] Developers requested to help provide >"completeness" tools > >On Mon, May 12, 2008 at 8:16 PM, David Earl <[EMAIL PROTECTED]> >wrote: > >> I think it is terribly hard to know whether you have all the footpaths, >> and I think we'd hardly ever mark anywhere "complete" if we did that. > >I think it's terribly hard to know when a map is correct and complete, >regardless of what you're considering. > >In fact, as something I've floated with some people before, I think >the idea of "completeness" is the wrong way round. I think we should >be considering where a map is *incomplete*. > >Think about it. If you are presented with a map of your village and >asked whether it's right, it's very unlikely that you know all the >roads and all the names and how everything connects and be sure of >yourself. But it's quite likely that what you'll spot (if anything) is >a mistake or a missing road. I can do this with TIGER stuff for >example - I can't tell you if the map is correct, but I can definitely >find bits that are definitely wrong.
Some of us map out an area completely in one go rather than doing it piecemeal. Even if I come across some existing roads in a new area I ignore them and do a new survey so that the whole area makes logical sence to me. That way I can work out where the landuse areas are behind the houses and the extent of school areas etc etc. So for me a reasonable level of completeness is easy to decide and annotate. I accept where many users touch the same area, especially areas with Y! imagery then this approach probably is not workable. Cheers Andy > >I've been considering what I'd do to Wandsworth and Fulham (my local >areas) if someone asked me to mark which areas are correct. I think >there's very little value in me doing so, since most roads I've only >been down once and hardly likely to check the name from memory. But >there's a couple of bits that are definitely wrong, and I can point >them out easily. > >It's just another way of thinking about it, but I think that >neutral/wrong is probably more useful than neutral/complete when >considering maps. And it certainly cuts out trying to define >'complete', since whichever reason something is wrong (name, >connectivity, missingness) it's very easy to state why it's wrong. And >rather than more and more being complete (for this, that and the other >definition of complete) there'll be fewer and fewer bits that are >wrong. > >Nobody ever looks at a map and remarked how many bits were correct. >Nor does any software product keep a list of lines of code that are >working. Or it's an 'exception driven' way of considering things. > >Cheers, >Andy > >No virus found in this incoming message. >Checked by AVG. >Version: 8.0.100 / Virus Database: 269.23.16/1429 - Release Date: >12/05/2008 6:14 PM _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
