I am afraid I am irritating you folks with my focus on errors in the OSM source data. If so, I just apologize for that in advance. Of course, as in the science and research generally, it is much more attractive to work on something new than working on something already done. OSM community is no exception and maybe therefore there is very little effort dedicated to errors, especially to systematic errors. Systematic errors are having same, or similar causes. They are present in a huge number and distributed all over the World. It is difficult to see them, detect them and correct/repair them. Usual editors based one-by-one correction is meaningless. The “DO-ocracy” principle does not work here and “diff”s based maintenance does not help either. These errors are accumulating, and (probably) permanently there and reflected in any publicly available OSM based mapping systems.
One could say – he must be wrong, he is using wrong source data interpretation and the like. But careful. What if I am right? What if these systematic errors really exist and accumulate. Well, we do not need to be scientists to understand where this leads in the long term. And this is my concern. But I feel I am pretty alone here. When I try to move the attention to these systematic error issues by discussing and asking questions, people are irritated and, eventually, formally answering them. Even if I attach obvious and unbeatable arguments I receive answers like: “I don’t see the problem”, “I don’t understand what are you trying to achieve”, “I am not here to argue with you”, ”Well, take an editor an correct the errors” and so on. Of course all these does not help the (OSM) community. Systematic errors should be prevented by eliminating their causes instead of curing the consequences. Let me give an example. Some days ago a mapper sked an the Help Forum the following question: “How to make a hole in an area, eg woodland.”. There were given 6 to 8 answers all incomplete (strictly taken – wrong) as how to upload a (new) complex area instead of how to convert an existing simple area into a complex area. Any of the instructions leads to existence of two almost overlapping areas one as a simple and one as a complex area (with a hole). The outer border polygons will lie in a thin corridor belt of each other (note, not overlapping) and the hole will never be visible. There is a huge number of these area error cases.
The number of systematic error classes, volume of each, the permanent nature of them… indicates to me that I am pretty alone here. So, if you share/have the same concern let us cope jointly. Even better, if already vi have a forum/list that should work on systematic errors, let us know which one is that and join them.
PS. More about systematic errors, their causes, examples, illustration… you may find (download from) here: