You can use different external sources to do different types of comparisons: 1. Garmin (or any other commercial) map: compare length of roads, number of poi's, addresses. 2. Municipality data: take lists of street names and calculate how many of those exist in OSM (how many streets exist in OSM but are not in municipality data - error streets) 3. Official number/length/area of rivers, lakes. 4. Official list of places. 5. List of national parks, theatres, museums. 6. Number of keepright.at errors (you probably need ratios to compare to results of other countries) 7. Data from commercial entities (shopping centres/networks, banks, restaurants etc.)
etc. I think you get the idea. Note that such external info could be used not only to assess quality and quantity, but to point out missing information and automatically detect deleted/crippled data or even detect errors in external sources. -- Tomas _______________________________________________ Talk-ZA mailing list Talk-ZA@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-za
