Edward Johnson >Sent: 25 June 2008 4:04 PM >To: [email protected] >Subject: [OSM-talk] The completeness of OpenStreetMap > >I'm compiling some research into ways in which we can think of a map as >complete and how complete OSM is. I was just wondering if anyone had any >thoughts on the topic. My initial ideas have been posted on my blog >http://edwardmjohnson.wordpress.com/ and I will continue to update this >until I'm satisfied I know everything there is to know about the >completeness of the map! > >One of the most interesting parts is how can we quote completeness of the >map? My first thought was a stage system as quoted below > >* Preliminary stage - GPS tracks gathered or area has yahoo imagery. > >* Stage 1 - Nodes and ways mapped onto OSM using GPS track or aerial >imagery. > >* Stage 2 - All roads named and roughly categorised > >* Stage 3 - Map good enough for satellite navigation. All one-way streets, >and restrictions tagged along with accurate street categorisation. > >* Stage 4 - All POIs (i.e. post boxes, bus stops, pubs, restaurants, >supermarkets etc.) tagged. > >These stages may or may not occur in sequential order and each stage can be >quoted complete in terms of percentages. For example we might say that >London is 100% complete for Preliminary and stages 1 and 2, but only 60% >stage 3 complete and 20% stage 4 complete. The hard question is how do we >accurately measure these percentages. > >What are other people's ideas?
Unfortunately it doesn't really work like that. We might have a very small part of a city that is stage 4 and then next door in the same city it might not even have reached stage 1. That's why I had a stab at looking at it a little differently and came up with http://wiki.openstreetmap.org/index.php/Completeness_Metrics but its not that scientific and is only intended as a guide to help focus mapping effort. Cheers Andy _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
