On Saturday 19 October 2013, Frederik Ramm wrote: > > I think that is the core of the problem. For many, the visual power > of the aerial imagery is so strong that any data not matching the > imagery is deemed wrong.
It seems to me instructions for beginners concerning mapping based on imagery could much better cover this matter. While the problem of position offset is frequently mentioned and illustrated in tutorials there is usually at most a simple 'be aware that things might have changed since the time the image was taken' concerning actual interpretation of the images. In my experience people for example usually only start to realize the problem of outdated images after actually seeing how things change in imagery over time (which they do not by looking at Bing etc. except if they consciously witness an image update). Interpreting aerial/satellite images is a difficult task and people who do this professionally usually spend a lot of time learning how to do it. It is not reasonable to assume that for the average OSM mapper this is so self evident that no explanation is necessary. None the less editors mostly show the images in the background and the mapper is essentially left alone with what to do with it. I think it is to be expected that there are quite a few mappers who then simply try to adjust the data to match what they see in the images by either changing, deleting or adding elements. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk