dare you to run simplify tool on anything remotely round, it will make it look like garbage
On Fri., Jan. 18, 2019, 3:49 p.m. John Whelan <jwhelan0...@gmail.com wrote: > The import mailing list was pointed to the correct page of the wiki. The > initial post was to say this is what we were thinking of and there was a > comment saying we needed to change the comment line. > > >There is no mention of this proposed import on the import catalogue > > > The import process was reviewed by the person who set up the Ottawa import > did we miss that step on the Ottawa import as well? Neither was it raised > as a concern on the import mailing list. I think this is very minor and can > be corrected. > > We learnt a fair bit on the Ottawa import and my expectation is since we > are using experienced mappers to do the import conflation would be either > handled by them or the building not imported. We aren't using new mappers > in a mapathon here and with experienced mappers then I think you have to > trust them. The world isn't perfect. Think in terms of service level. > > >There are 2X more nodes than needed to represent the building accurately. > > The problem with correcting this is you are introducing approximations. > This will vary according to the source and this can be simplified or > corrected once its in OSM. I think this is a different issue of a > mechanical edit that needs to be considered separately. > > If we are concerned with database size then I suggest we change the > instructions to say put the source comment on the change set rather than on > the building outline. > > Cheerio John > > > Nate Wessel wrote on 2019-01-18 3:06 PM: > > John, > > You seem to be playing the long game with this data - it sounds like > you've been working with this a lot longer than I have, and you've put in > the time and effort to help make this actually-quite-incredible dataset > available to us. I don't want to stop the import from happening - quite the > opposite. I just want to make sure that the time is taken to do this right. > OSM deserves that. Your (our) long awaited victory will be the sweeter for > our patience now. > > There are several specific issues I see where the I's are not crossed, nor > the t's dotted. I've mentioned several already, so I'll try to be brief (I > really need to get back to working on my dissertation). > > 1) There was extremely limited discussion on the imports mailing list. The > initial email did not make clear the scope of the project. I read the email > and did not think twice at it, thinking it was entirely about Ottawa. The > link in that email was actually to the Ottawa import, and not this one, > which seems to have been only in draft at the time. > https://lists.openstreetmap.org/pipermail/imports/2018-November/005812.html > As such, this project has NOT been reviewed by the imports list, which is > a requirement for proceeding with the import. > > 2) There is no mention of this proposed import on the import catalogue ( > https://wiki.openstreetmap.org/wiki/Import/Catalogue) > which is required in the imports guidelines. I suspect many other > guidelines have not been followed. > > 3) The wiki page describing the import is not adequate to assess the > quality of the data or of the proposed import. See for example: > https://wiki.openstreetmap.org/wiki/WikiProject_Canada/Canada_Stats_Canada_Building_Outlines_Import/Plan#Risks > The import guidelines call for a description of how conflation will be > handled. The fact that two of the major importers seem to have a > substantial disagreement about how to handle existing data indicates this > was not well discussed and I can see that it isn't well documented. > > 4) The buildings need to be simplified, quite a bit actually. Most > buildings have multiple nodes representing straight lines. This bloats the > database and makes things harder to edit by hand later. There are probably > 2x more nodes than are needed to represent the data accurately, making it > harder for editors and data consumers to work with down the road.This is a > simple fix that will save countless hours later. > > ... I could go on, but I think this is plenty sufficient to justify > pressing pause on all this. > > Again, I don't in any way want to disrespect the work that has gone into > this effort already. We're all volunteers here and I know how much time > this all takes. However. importing all/most of the buildings in Canada is a > monstrously large task, which will have to dance around a lot of people's > toes. We should expect this to take a really damn long time if we're going > to do it right. We need to have the patience to learn from experience, from > critique, and from the wisdom of the people who've learned from flawed > imports in the past and have devised guidelines and processes so that we > can have better experiences with this in the future. > Nate Wessel > Jack of all trades, Master of Geography, PhD candidate in Urban Planning > NateWessel.com <http://natewessel.com> > > On 1/18/19 2:24 PM, john whelan wrote: > > My background is I'm a retired civil servant who has written and overseen > procurement documents and fairly large procurements. Dotting the is and > crossing the Ts are my speciality. > > There are two parts to an import. The first part is the part played by > the import mailing group. They confine themselves to is the license > correct and do you have a reasonable plan. In this case the license is one > of the few that has been confirmed by the Legal Working Group of > OpenStreetMap and as such no questions were raised about it on the import > mailing list. We have methodology that has been used before successfully > with the Ottawa building outline import. There were major discussions both > on talk-ca and the import mailing group before that import took place and > we took note of the issues raised and addressed them. The licensing issue > goes back about eight years to when I was talking to Federal Government > Treasury Board and explaining their Open Data license did not align with > OSM. That is why their license is now known as 2.0. > > The second part is the local group makes the decision to import they are > the authority no one else. > > Apparently you were not part of the talk-ca when the discussions took > place which would have been the time and place to raise concerns. > > When the Ottawa import was done there were one or two places where the > existing buildings and the import overlapped. In the instructions on the > import there are instructions to cover this. Specifically there is a > validation step. I seem to recall the error rate was of the order of 1% > and I expect this latest batch to be roughly the same. > > If you can identify which municipalities data is of poor quality then I'm > sure we can remove these. For the most part these are from the foundation > plans recorded by the municipality using professional surveying techniques. > > Would you like to clarify exactly where I failed to dot the Is and cross > the Ts please. > > Many Thanks > > John > > > > On Fri, 18 Jan 2019 at 13:37, Nate Wessel <bike...@gmail.com> wrote: > >> Hi John, >> >> As Steve has said, you seem to be the only one suggesting that thousands >> of import committees might need to be formed. Certainly I'm not suggesting >> that. >> >> My understanding of OSM import procedure (and wiki-style projects more >> generally) is that imports should operate in an essentially consensual way >> where possible. The goal is to build consent and bring people on board with >> a project or a change by addressing their concerns in a meaningful and >> respectful way. >> >> I think that I have made some substantive and troubling claims about the >> quality of the data being imported. I've pointed out that this project has >> not followed the import procedures that were produced by a community of >> mappers larger than just those in Canada. >> >> So to respond to your implication, I am in some sense the one reviewing >> the project, just as I would welcome you to find ways that my own >> contributions could be better. If you want my credentials for reviewing >> your work, here they are: >> >> 1) I am an active contributor to OSM in Toronto, where I live (and >> elsewhere) >> >> 2) I am currently helping to lead a building import in Hamilton County >> Ohio that has better addressed some of the issues I see this import >> struggling with. I can help you do the same. >> >> 3) I've been doing research in GIS for a long time now, though I don't >> need that to tell you that the issues I've described are hardly >> insurmountable technically or even all that difficult to fix. It would take >> maybe one day's hard work to get the technical side of this right. >> >> I think Canadian OSMers will agree that we can take a pause to get things >> right on such a massive import. If they don't - if I'm shouted down or >> better, if my critiques are adequately addressed, then I will leave you to >> finish the project in peace. I might even lend a hand if all goes well, as >> I sincerely hope it does :-) >> >> Best, >> Nate Wessel >> Jack of all trades, Master of Geography, PhD candidate in Urban Planning >> NateWessel.com <http://natewessel.com> >> >> On 1/18/19 1:11 PM, john whelan wrote: >> >> I know of no other way to contact him but he made an interesting comment >> that the project is on hold in the wiki pending review. >> >> Would he care to comment on who is supposed to be reviewing the project? >> >> My understanding is that the import was raised in talk-ca before it >> commenced for comment and these were generally favourable. I took that as >> the local mappers to Canada had been consulted and they are the "local >> mappers" authority in this case. >> >> I understand he has concerns about local mappers making decisions but in >> Canada we have been importing similar data through CANVEC for some time. >> CANVEC data comes from a number of sources including municipal data. >> >> Is he suggesting that each of the 3,700 municipalities in Canada should >> form a group of local mappers who can make individual decisions on whether >> their municipal data should be imported and we should end up with 3,700 >> import plans? >> >> Thanks John >> >> >> >> _______________________________________________ >> Talk-ca mailing >> listTalk-ca@openstreetmap.orghttps://lists.openstreetmap.org/listinfo/talk-ca >> >> _______________________________________________ >> Talk-ca mailing list >> Talk-ca@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/talk-ca >> > > -- > Sent from Postbox > <https://www.postbox-inc.com/?utm_source=email&utm_medium=siglink&utm_campaign=reach> > _______________________________________________ > Talk-ca mailing list > Talk-ca@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ca >
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