Changeset: 39517002
adding lakes
Closed by Rps333
Tags
created_by | JOSM/1.5 (10168 en) |
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source | CANVEC |
Discussion
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Comment from Nakaner
Hi Rps333,
I am going to revert this changeset in the next hours due to following reasons:
1. Import using no dedicated account (i.e. violation of Import Guidelines)
2. bad import because of uploading data which is clearly broken (ways with natural=water which are not closed). Your editor (JOSM) has been reporting this error for more than five years.
I did not have a look if the import documentation is ok because there are enough reasons to revert this huge (> 15k objects) changeset.
This changeset has been found using To-Fix.
Best regards
Michael
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Comment from Rps333
Hi
I will check the errors you are talking about tonight. Please wait.
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Comment from Nakaner
Hi Rps333,
I won't wait.
If an import is bad and/or violates the guideline, everyone can revert it. I will have a look at your other changesets which I consider as imports and will revert them, too, if they seem to have the same systematic errors than this changeset.
JOSM has an built-in validator which checks for error. If you do an import and upload it without checking the results of the validation, it is at your own risk that your changeset will be reverted. There might be months or years between your upload and the revert.
Best regards
Michael
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Comment from Nakaner
Changesets 39517571 and 39517686 have the same problems as this changeset: unclosed ways. Changeset 39517944 and 39518147 have a different problem: You added lakes inside lakes.
Within 34 minutes (19:30–20:04), you created 35,972 objects (1058 objects/min). A manual tracer who checks his traced objects while tracing can achieve maybe 100 objects per minute (example of fast tracing, 43 objects/min: changeset 38202316). The errors of your changesets proof that you just did an automatic object creation and bulk upload without any manual oversight.
OSM is no open data collection service. Its a project of hand-made (some call it "craft mapping") geospatial information. If you want to have a simple collection of open data, you can just bundle a dozen of shapefiles/GeoJSON files together as a tarball.
I had just a look at following changesets before I wrote this text: 39517414, 39517571, 39517686, 39517944, 39518147.
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Comment from Nakaner
The revert has been started. https://www.openstreetmap.org/changeset/41749133 and following changesets.
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Comment from Nakaner-repair
This changeset has been reverted fully or in part by changeset 41756737 where the changeset comment is: Revert low-quality CANVEC import due to violation of Import Guideline and technical errors. See discussion of changeset 39517002.
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Comment from Rps333
Why? I had fixed most if not all the errors you noticed. What are your guideline for determining poor quality?
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Comment from Nakaner
Yes, you fixed some errors but there have been left still enough errors which justify a revert.
Unclosed polygons, liquid islets (natural=water inside natural=water), wetlands overlapping with water are the main problems of your import.
In addition, you violated the policy by not using a dedicated import account. https://wiki.openstreetmap.org/wiki/Import/Guidelines#Use_a_dedicated_user_account Any violation of the guideline justifies a revert.
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Comment from LogicalViolinist
Nakaner, I think you should have discussed your rollback on the talk-ca mailing list to decide what to do. Rps333 does fix his errors and is a very active mapper. Adding lakes and rivers around native reservations is quite useful to Canadians.
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Comment from Rps333
So, if I used an import account it would be OK?
Could I have just remove all the wetlands?
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Comment from Nakaner
Hi Rps333,
if you used a dedicated account and check all your uploads before you upload them, you would take the wind out of the sails of people like me.
Please note that not every error can be detected using JOSM's validation engine. If you upload data which is simple wrong (compare the data with satellite imagery you are allowed to use as data source – you might have a look at other Landsat imagery than the one used by Bing), your edit still might be reverted. If you do not invest the time to check the quality of your uploads, you cannot expect other mappers to preserve your edits (i.e. not revert it).
If your import is as bad as the examples of Worst of OSM (worstofosm.tumblr.com), it is just a matter of time until it and all similar changesets will be reverted.
Please keep the history of existing OSM objects. If someone has already mapped something in the area you want to import, you have to preserve this history and must not delete the old data and replace it by yours.
Additionally, I ask you to upload your data in smaller chunks, i.e. no changesets with more than 2500 objects at once.
By the way, has there ever been on-the-ground quality of Canvec's hydrological data (water areas and waterways)? Or do all Canadian mappers just trust that the people who produced the data did everything right? (OSM isn't a copy of public datasets)
Best regards
Michael
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Comment from Kevo
"been on-the-ground quality of Canvec's hydrological data"
If you're talking about on-the-ground checks in areas like this changeset, you've proven that you're unqualified to make decisions on data in a country that is 30 times bigger than your own. This land is still essentially unexplored and a vast majority of it is impassable even on foot.
If you're going to mass revert areas far outside the realm of your knowledge, at least send a message to the talk-ca list instead of unilaterally reverting changes from 6,000km away while preaching that this is a "craft mapping" project to users who actually understand their country.
It's cute when Europeans think they understand Canada and it's been getting on my nerves for a while.
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Comment from Rps333
Michael, I always check the data against Bing/ Mapbox imagery/ NRCan Map in JOSM. In this area the imagery is very poor.
I also alway check if the CANVEC data is better than what is already there. Not alway the case.
I added one layer at a time; roads (if required), water, streams and sometimes wetlands. The woods layer in CANVEC in my option is usually very poor, and most of Canada is woods anyway so I never use it.
I also tend to only add data to unmapped Northern Communities around James Bay and Nunavut. (Nunavut is over 2 million km2 and has a pop of about 30K)
I also alway run the validation in JOSM. But for some reason it does not pick up the broken lakes. Not sure why.
I understand problems that bad imports over area where there is all ready data can cause. (Most of my edits are done with ID).
But there are huge areas in Canada with no data at all, so CANVEC must be used.
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Comment from Nakaner
I do not claim that every lake has to be checked on the ground but some secpscepticism about third-party datasets is always a good idea.
Has ever been an OSM mapper in Northern Communities around James Bay and Nunavut and can say if the lakes at CANVEC match the reality? If you do remote sensing (outside OSM), it is a good idea to pick out some samples to check if the classificiation works as expected (or to train the classification algorithm/rules).
Regarding the JOSM validator: This check might be disabled at your JOSM. Maybe you delete your JOSM profile and created a new one with default settings?
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Comment from jfd553
All available Canvec data in northern areas were checked less than 10 years ago using much higher resolution imagery than what is available in OSM. Everything is not perfect but way much accurate than nothing.
I used to work on the checking process mentioned above! -
Comment from the506
In addition, most of these communities are tiny (<1000 people) and often do not have quality Internet access. The chances of there being active local OSM mappers in these areas are essentially zero.
For all its faults, CANVEC is literally all we have in these areas, and given the sheer size of the north, it's just not worth it to spend hours per tile going through everything with a fine tooth comb.
Nunavut is not Germany.
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Comment from LogicalViolinist
Not to mention that Bing Imagery can be older than CanVec itself (10-15 years or more)
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Comment from mikelmaron
> I won't wait.
This is not OK.
OSM only works with cooperation and respect. We find ways to help support each others work and make the map better. The work of this changeset is led by active mappers in an active community, who are ready to discuss and work on their data. Certainly there can be improvements, and we can work together to get there.
There are very few situations where a unilateral and immediate revert is justified (like active vandalism), and possibly zero where such an action would be taken without consulting the DWG, and especially where the mapper is willing to actively engage in discussion of the issue.
Let's figure out what conversations we need to have and guidance we can put in place, so that our community remains a welcoming and cooperative place for making the best map in the entire world.
-Mikel
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Comment from Nakaner
I have sent an email to the Talk-ca mailing list via Gmane. I hope it arrives. Otherwise I'll resent it the normal way. (I have subscribed the list)
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Comment from Rps333
Ref JOSM validator: I have deleted my JOSM profile. It now picks up the broken lakes. Thanks for the info.
I will be happy to fix the broken lakes and any other problems that are in this change set.
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