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Node density

Posted by leuty on 23 February 2013 in English (English)

The node density (number of nodes per way) is a measure for trust (uncertainty) for the location of a way. The more nodes we add per way, the bigger the confidence we signal to data consumers and fellow mappers. IMHO, it is not wise to choose a high node density, if I am not very sure that I actually add information to the database and not only noise.

Particularity this holds true for data imports. Even if the data source claims a certain accuracy, we can not be sure that this holds true. If you import any data, please be aware of this and choose your node density very conservatively (unless you have verified it yourself). We can still improve the exact location later on by hand. I know this takes longer, but Rome wasn’t built within a day either. We wan't to build the best map of the world and not the largest database.

In the recent days I manually removed a huge number of nodes from CanVec imports. I know that I also removed valid information during this process. But the benefits (a node density that reflects uncertainty) are larger than the costs (loss of a small amount of valid data). Instead of arguing with each importer individually (which I have done over and over), I thought that I should raise awareness here.

Thx for understanding.

Wierd looking streets, what to do?

Posted by leuty on 23 January 2013 in English (English)

Hi Community

While fixing connectivity errors using maproulette (its fun btw.) I found the following location in Medicine Hat, CA.

http://www.openstreetmap.org/?lat=50.06165&lon=-110.69818&zoom=16&layers=M

The streets mapped by user Yorii are done very strange (not connected, messed up connection of other roads). IMHO this seems a bit like someone was toying around with an editor (if not I apologize in advance). I can't find these roads on Bing either. It could very well be that they were added after Bing img was taken. It is hard for me to verify this form my armchair in Europe.

Is there newer Imaginary available for this region? Or is anybody living there who could go out and verify their existence?

Thanks and again. Sorry if I make false acquisitions, this is not my intention.

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