Apologies for the length, but there are quite a few points to "address," some of a specific nature and others more general. Because I'm replying to points across several messages and the formatting in this thread has become screwed up I'll be reformatting messages and re-ordering them so that they make more sense. Imports, as you can probably tell, are an area I care about.
Full disclosure: I maintain ogr2osm, the software used for converting geometries in the proposed import. See https://github.com/pnorman/ogr2osm for more information. While I support address imports in principle it is important that they are done right. Back in 2010 I did an address import and although on the whole it was successful I learned some lessons. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001602.html > From this page: http://wiki.osm.org/wiki/Import/Guidelines#A_checklist, > can you advise as to the checklist steps we are not following, or which steps > should be added to this checklist? http://wiki.osm.org/wiki/Import/Guidelines#Discuss_import_with_community requires that consultation be done with imports@ and the appropriate local communities. This certainly includes talk-us@. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001598.html > The current plan is to focus on addresses and building outlines. > Sources are currently suggested to be tagged as: > source:addr=data.seattle.gov > source:path=data.seattle.gov > so as to accomodate other sourcing information for those points and ways, as > appropriate. The value of source=* tags on objects is debatable. Source tags on changesets are a very good idea but it's not clear if they're a good idea for objects. There are arguments either way. I am working on an as yet unproposed address import and in the initial version I will be proposing I will not be adding source tags to objects. If after consideration you do decide that source tags are worthwhile I would recommend just source=data.seattle.gov. This corresponds with the general practices for the use of source tags. Remember that source tags exist for the convenience of mappers and if they become inconvenient they are not worthwhile. Source tags that are long and cryptic do not help mappers. Some imports have used source tags where it necessary to look up the exact value of the source tag because it was so long and complicated. I quickly found that it wasn't clear what to do with the source tags when editing the addresses, primarily to merge with buildings or POIs. If it wasn't clear to me, the importer, I'm pretty sure it was unclear to other editors. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001602.html > > How will you handle object conflation? > Manually and methodically. Although not a trivial problem there is work underway on code that will handle the address-address conflation (https://github.com/pnorman/addressmerge). Address-POI and address-building conflation remains a purely manual job. It shouldn't be too hard to merge addresses with buildings they are within when the building has only one address within in and the building does not itself have an address. Addresses placed by building doors outside the building itself add complications but I expect they are solvable. Having said that it shouldn't be too hard, it's not trivial. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001602.html > > Where is the source of your transformation scripts? > From the email above: "some translation instructions Cliff has put together." > We will include the specific translation code either at a github page or on the > http://wiki.osm.org/wiki/Seattle page. > > Where are the specific data files you're transforming? > They are at data.seattle.gov & we will provide links to the sources. > We will also consider posting separate snapshots of these source > datafiles if we can figure out where to host them. To be able to sensibly comment on the tagging and data quality we really need a sample .osm showing what the data is like. One option for hosting it is an account on the dev server. See http://wiki.osm.org/wiki/Dev_Server_Account for more information on this. If this is a problem you could email me a file and I could host it on one of my servers. Because I maintain ogr2osm I'm comfortable reading very complex translations and determining the results without actually running the code. Most people aren't and a .osm file is a good way for people to access the tagging and data quality. Another option for documenting tagging is an appropriate page on the wiki. When I was working on the Alaska county import I documented the tagging I would be using at http://wiki.osm.org/wiki/Alaska/TIGER_Counties#Tagging before I had written the translation file. The correct tagging for the county data was pretty obvious. It also gave me a chance to document the changeset tagging. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001606.html > We identified these files and developed preliminary scripts a couple days ago. > Here are a couple - these may not be the only sources considered for import: > https://data.seattle.gov/dataset/Master-Address-File/3vsa-a788 > https://data.seattle.gov/dataset/Street-Network-Database/afip-2mzr > https://data.seattle.gov/dataset/2009-Building-Outlines/y7u8-vad7 I would recommend holding off on the streets data and restricting this to addresses and building outlines. Virtually every aspect of imports involving street data is significantly harder than other imports involving only buildings and addresses. I strongly recommend you start with this data as you so you gain some experience first. Even writing a good streets data translation is generally harder. When you've finished with the addresses and buildings you could then propose a new import for the streets. We are also likely to have better tools for dealing with the streets data in the medium term. Jeff Meyer @ http://lists.osm.org/pipermail/imports/2012-December/001606.html > I'm not sure why you are asking if I'll be doing this myself. This > email thread contains several references to people who will be > assisting. Cliff Snow and others attending the meeting to discuss this > import. We hope to have a team of local mappers focus on imports where > they have local expertise. CanVec, French cadastre and other imports where the data is made available to multiple people (e.g. through a website) show that without a QA process the quality of imports varies drastically from person to person and that you'll see some real bad imports. That's not to say that it can't work and in many ways it's a preferable process but one bad importer can easily create a mess in minutes that takes others ages to clean up. One way to mitigate this is to do as much post-processing as possible before releasing the files. In the context of address this would mean removing the addresses that duplicate existing OSM data or for buildings removing buildings that intersect existing buildings in OSM. As the word count is telling me this message is over 1000 words I will leave aside some concerns I have with updating and conflation for another message later. _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
