Talk:Quality assurance
Discuss Quality Assurance here:
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Undo
I would like to add (or see :-) a section about "Undo changes / how to get information about "who did add/change/..." / vandalism and how to revert the data (if possible), but before I start investigating the topic I would like to get some opinions about it. So: opinions? Drbobo 10:39, 11 December 2008 (UTC)
- On this page there is a program called osmdiff. You can use it to monitor an area of interest. It will tell you who did what. It cannot undo anything unfortunately. --Gary68 13:39, 11 December 2008 (UTC)
- I wonder whether it is possible to revert the data, eg. after vandalism? Seems that currently there is no chance to revert it, http://wiki.openstreetmap.org/index.php/Talk:OSM_Protocol_Version_0.6. --Drbobo 16:00, 13 December 2008 (UTC)
- See Change monitoring and Change rollback. For a run down of the (limited) techniques available at the moment. It's more technically tricky to revert changes on a map as compared to a wiki, but this is direction we developing in. -- Harry Wood 18:24, 15 August 2009 (UTC)
Remove unnecessary nodes
There are a lot of highways with nodes in a straight line. I think it would be a good idea to remove those unnecessary nodes with the utilsplugin of JOSM (simplify way). Less nodes = faster map drawing and less database size. With a simplify-way.max-error setting of 1 (m) there won't be any details lost. --GP4Flo 22:23, 12 August 2009 (UTC)
-- Lesson, don't throw away data you a don't understand. Unfortunately when GP4Flo edited/simplified a great amount of data he throw away a lot of very accurate information I had been amassing over a long period of time. Many of the paths that were accurate to less than a metre are suddenly missing nodes because the tool was ran with a large max-error setting. This type of behaviour should be considered VANDALISM and will drive away users with access to good data. Alpine walking tracks were effectively changed to straight lines! This tool should be used on individual traces and not on the complete dataset.
We have already talked on PM about the problem. The default max-error-setting was set to 2.5 (meters) which is a bit too high for some very small details. I'm sorry that this was the case with some of Evan's nodes. Changing the setting to 1 m should avoid such problems. In my opinion it's the question whether it does make sense to draw super-detailed paths out of GPS data which is only measured with an accuracy of (for the best case) about 2 m. I've used the simplify option on a lot of paths I've collected with my GPS and couldn't notice any loss of important detail. You won't be able to see a difference of 1 m in your GPS device or in the slippymap anyway. --GP4Flo 12:47, 31 August 2009 (UTC)
- Although we can't see a error of 1 meter in the slippymap for one way (as in most rural locations with current data density), it becomes quite visible once there are other features that have been positioned relative to that way; say a hedge, building or a cliff that was seen to be parallel to the road at that point and 6 meters away from the centerline (lane 3.5m + sidewalk 2.5m): if the "extra" node is removed from the road, the feature next to the road would then be at a wrong angle and possibly even overlapping the road. Just something to be aware of when simplifying in areas with other features present. Alv 15:01, 31 August 2009 (UTC)
List of all QA tools and services
Hi, would it be better to collect all QA services here or there: List_of_OSM_based_Services ? --!i! 16:53, 8 August 2010 (BST)
- We've had this page for a long time as a useful list of OSM data bug detecting/analysing/reporting tools. These tools are very much within the ecosystem provided entirely for mappers to improve the data.
- The List of OSM based Services ...is a list of OSM based services. i.e. services for people outside of the OSM world, but using OSM data/maps.
- -- Harry Wood 10:15, 9 August 2010 (BST)
- So ok I will add the tools to the list and add a nice list of the related tools here, too --!i! 12:21, 9 August 2010 (BST)
Cleanup Request
Hi, would be great is someone can resort the items e.g. into:
- bug reporting
- monitoring
- error detection
- assistants
Linking to List of OSM based Services, ... would be cool, too --!i! 
13:57, 4 November 2010 (UTC)
- I made a proposal for the order based on your idea. The List of OSM baded Services is linked at the end of the site under "more" or do you mean a more prominent way? --DINENISO
Tool for highlighting dead weblinks
A Quality Assurance tool for highlighting dead web links where 404 errors occur for the website tag. Should be a useful way to help people update old web addresses when things change?--Hawkeyes
Yes, website=* tags. --Hawkeyes
FLOSM
I added FLOSM to the QM site. The contribution was reverted because of copyright issues with this service. My questions to prevent potential future copyright problems:
- Why are the road lists, where each missing street has a link to google maps, OK where this site is not?
- For which task is FLOSM written, when we are not allowed to use it for QM?
- Is OSMcompare also illegal?
Thank you very much --DINENISO 21:20, 10 April 2011 (BST)
- The road lists thing you mentioned sounds like it could bad idea too. I haven't looked into it.
- It's clear that we shouldn't use FLOSM to copy roads from teleatlas, and using it to gain a rough idea of levels of completeness is also something OpenStreetMap contributors should not be doing. External people assessing OpenStreetMap's completeness will inevitably use tools like this to make a comparison. We should avoid feeding that directly into our processes for contributing or deciding where to go mapping.
- OSMcompare is also problematic. I wouldn't say illegal. As I say, people will inevitably create and use comparison tools. But it is quite likely to be illegal for OpenStreetMap contributors to use comparison tools for their contribution, because basically you're copying.
- There's some tricky grey areas here, but fundamentally we're creating an open licensed map by re-surveying the world from scratch. That's the idea of the project. This Quality Assurance page should avoid listing such tools altogether. On the wiki in general we should either avoid linking to comparison tools, or make it very clear that contributors should not be using these tools while mapping.
- -- Harry Wood 11:42, 11 April 2011 (BST)
- Thank you for clarification, then services like OSMcompare and FLOSM perhabs should be listed in the List of OSM based Services when they are intended for external use only. --DINENISO 12:55, 11 April 2011 (BST)
- Perhaps. Although we should label them clearly. Maybe a compact way of saying this is "Not to be used as a source"
- But I'd also recommend creating dedicated wiki pages. This is always a good way of giving us plenty of space to express ourselves more clearly. If we had a page on FLOSM and OSMcompare then we could write some clear guidance on there.
- -- Harry Wood 22:33, 11 April 2011 (BST)
- Harry, could you please clarify why you see the use of tools like these by mappers as a problem? As long as they are used only to find out areas where we need to collect more data (on the ground or from aerial imagery with permission, NOT from the maps we compared to), I can't see where copyright would be involved. But as I'm not familiar with common-law based legal systems I might be missing something here. --Lyx 22:46, 11 April 2011 (BST)
- See Completeness#License issues (Note that this page was written by me, but please feel free to discuss and adjust the text to reflect consensus) "As long as they are used only to find out areas where we need to collect more data"... fine but now let's just zoom in a bit, and oh look, we've just exactly identified a missing street. Might as well just copy the map. If you list a tool like this on a page along with lots of other quality assurance tools for mappers, that's definitely going to give people the wrong idea. -- Harry Wood 23:12, 11 April 2011 (BST)
- Harry, could you please clarify why you see the use of tools like these by mappers as a problem? As long as they are used only to find out areas where we need to collect more data (on the ground or from aerial imagery with permission, NOT from the maps we compared to), I can't see where copyright would be involved. But as I'm not familiar with common-law based legal systems I might be missing something here. --Lyx 22:46, 11 April 2011 (BST)
- Thank you for clarification, then services like OSMcompare and FLOSM perhabs should be listed in the List of OSM based Services when they are intended for external use only. --DINENISO 12:55, 11 April 2011 (BST)
- Well for this kind of mapping applications we maintaine a list at Maps#Compare, so wouldn't this be a better place? --!i! 11:47, 5 September 2011 (BST)
Public transport validator
The links on Public transport validator are dead. I couldnt find the correct links but maybe anyone else knows them. Ogmios 07:48, 27 February 2012 (UTC)
- Hello, a few months ago the PT map openptmap.org has moved to a more powerful server. It seems I forgot to care about the validator, SORRY! However, I'm not sure if the validator project is active at all. I will try to contact the maintainer and keep you up-to-date. Meanwhile you can reach the Validator here. It is still running on the opengastromap.de's server, but I'm not sure if it's working correctly. --Marqqs 18:09, 27 February 2012 (UTC)
