I will point out here that iD has invented a new changeset tag which I find useful. It automatically records what imagery layers you use while editing and throws them into an imagery_used=* tag. This removes the need for users to manually tag source information if they are just tracing imagery. I wouldn't mind seeing other editors adopt this convention.
Toby On Sat, May 18, 2013 at 11:12 AM, Christoph Hormann <[email protected]>wrote: > On Saturday 18 May 2013, Yohan Boniface wrote: > > On 05/18/2013 03:55 PM, malenki wrote: > > > Dave F. wrote: > > >> IMO Source should be on the object, not on the changeset. > > > > > > +1 (except if there is one changeset for one object (; ) > > > > This is not my opinion. Let's take a simple example: a school. > > > > [...] > > The problem is currently neither changeset nor object tags are really a > good solution for true metadata (that is information characterizing the > data and not the real world object). > > Changeset tags have mainly two problems: > > - they always apply to the whole changeset so everything you map > together needs to have the same metadata. This might seem to be a > problem primarily for imports but it can also be troublesome in manual > mapping - imagine mapping something based on satellite images and you > need to use different images for various parts due to clouds or even > the common case of supplementing survey data with Bing images. > > - many large objects are included in a lot of changesets without > actually being substantially modified (like moving a single node in a > 500 node way etc.) This means finding the actual changeset a certain > geometry originates from to get the metadata information is not so > easy. > > The solution in my opinion would be to have separate metadata tags which > are reset everytime a substantial change is made to the data they refer > to unless the user explicitly sets them (either individually or for the > whole changeset). Geometry metadata tags for example would be reset > if: > > - in case of a node the node is moved > - in case of a way more than X percent of the nodes are changed (X being > something like 30) > - in case of a multipolygon more than X percent of the ways are > added/removed or substantially modified > > This would not be fool proof of course (small changes could accumulate > to a substantial change without being noticed). > > Greetings, > > -- > Christoph Hormann > http://www.imagico.de/ > > _______________________________________________ > talk mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk >
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