Re: [talk-au] PSMA Administrative Boundaries
On Wed, 16 Sep 2020 at 10:44, cleary wrote: > Thanks to both Andrew Davidson and Andrew Harvey for their work as I see > addition of PSMA administrative boundaries as an important improvement for > our map. > > In regard to adding source tags to objects, I find them very helpful when > editing something. If I think I have contrary information, I refer to the > source of the existing data. If it is an authoritative source, I am > prompted to go back and check my own information. Where information is > unsourced or refers to a less authoritative source, then I am more likely > to proceed with the edit or attempt to contact the mapper who entered the > previous information. Also I hope that by adding authoritative sources for > my edits, other mappers will be less likely to make changes without > contacting me or at least double-checking the accuracy of their later > information. If information comes from multiple sources, then it may be > appropriate to have multiple source tags e.g. source:geometry, source:name, > source:alt_name etc. I listened to a talk by Maurits van der Vlugt about "authoritative data" once (slides https://www.slideshare.net/MauritsV/authoritative-data-must-come-from-an-official-source ). I think we give too much credit for so-called "authoritative data". Just because the government publishes a GIS file of LGA and suburb boundaries, doesn't mean it's 100% accurate because it's not, and so we shouldn't treat these objects in OSM as immutable (I know you're not claiming that). In regard to relations, it is possible to have different sources for the > relation and for component ways, Yes this is exactly how the import candidates have been prepared, I'm in support of the source:geometry=* on the way, it's just the source=* on the relation, especially where there will be many other tags added later that I'm not so sure about. Ways often get split, and so checking the history to find the source can be difficult, but this isn't much of a problem for the relations. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] PSMA Administrative Boundaries
Thanks to both Andrew Davidson and Andrew Harvey for their work as I see addition of PSMA administrative boundaries as an important improvement for our map. In regard to adding source tags to objects, I find them very helpful when editing something. If I think I have contrary information, I refer to the source of the existing data. If it is an authoritative source, I am prompted to go back and check my own information. Where information is unsourced or refers to a less authoritative source, then I am more likely to proceed with the edit or attempt to contact the mapper who entered the previous information. Also I hope that by adding authoritative sources for my edits, other mappers will be less likely to make changes without contacting me or at least double-checking the accuracy of their later information. If information comes from multiple sources, then it may be appropriate to have multiple source tags e.g. source:geometry, source:name, source:alt_name etc. In regard to relations, it is possible to have different sources for the relation and for component ways, e.g a relation for a waterway may show the source of information including the name sourced from a permitted government dataset but component segments of the waterway may be sourced from two different satellite imagery sources. Again, I find sources helpful. Even state boundaries need verifying. At one time (not sure if it still the case) some SA Govt data showed some SA localities and protected areas as extending into NSW along parts of the shared border. After looking closely, I moved the OSM boundary slightly in some areas (generally preferring the NSW LPI data) but I was always careful to show the source of my data so that other mappers could verity or challenge me if appropriate. Some administrative boundaries in OSM were sourced from ABS data which were always just approximations. ABS data was useful in OSM when we had nothing else, but not now that we have accurate data from official sources. I have found it helpful to know the sources of the data I am looking at. On Tue, 15 Sep 2020, at 12:53 PM, Andrew Harvey wrote: > Resurecting this old thread as Andrew Davidson has been working on this > import plan a bit more -> > https://wiki.openstreetmap.org/w/index.php?title=Import%2FCatalogue%2FPSMA_Admin_Boundaries&type=revision&diff=2034132&oldid=1918537 > > Surfacing a few points from my review: > > 1. psma:loc_pid. Where this is a stable ID that is used as a reference, > the existing ref tag is better for this. If we want to be more specific > then ref:psma or something like that would work. No need to invent new > tags here when one already exists, is well documented and in widespread > use. > > 2. Regarding source tags on objects, this might be something I added > originally, I can't remember, but I'm on the fence about it. While on > one hand I can see it being helpful for mappers to understand where > these were sourced from, over time as people make changes in OSM the > source tag becomes inaccurate. I've seen this with existing source > tags, where people generally don't remove them if updating based on a > different source. Since you can always inspect the history to find the > source, is there really any benefit to having these on each object? > Given a whole bunch of other tags like contract details, website etc. > for LGAs can be added to, a top level source tag is not perfect. I'm > good with source:geometery on the ways, but not sure about source on > the relations. > > 3. More of a question for Andrew Davidson, is the plan for the actual > upload to go through the state borders and other ways already existing > in OSM, and delete the one with FIXME from your candidates, and use the > existing state border as part of the new relation? The "import" upload > should immediately be correct and not a broken state until post-import > changes clean things up, it should be uploaded clean in the first > instance. So this means manually working on it in JOSM before uploading. > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] PSMA Administrative Boundaries
Resurecting this old thread as Andrew Davidson has been working on this import plan a bit more -> https://wiki.openstreetmap.org/w/index.php?title=Import%2FCatalogue%2FPSMA_Admin_Boundaries&type=revision&diff=2034132&oldid=1918537 Surfacing a few points from my review: 1. psma:loc_pid. Where this is a stable ID that is used as a reference, the existing ref tag is better for this. If we want to be more specific then ref:psma or something like that would work. No need to invent new tags here when one already exists, is well documented and in widespread use. 2. Regarding source tags on objects, this might be something I added originally, I can't remember, but I'm on the fence about it. While on one hand I can see it being helpful for mappers to understand where these were sourced from, over time as people make changes in OSM the source tag becomes inaccurate. I've seen this with existing source tags, where people generally don't remove them if updating based on a different source. Since you can always inspect the history to find the source, is there really any benefit to having these on each object? Given a whole bunch of other tags like contract details, website etc. for LGAs can be added to, a top level source tag is not perfect. I'm good with source:geometery on the ways, but not sure about source on the relations. 3. More of a question for Andrew Davidson, is the plan for the actual upload to go through the state borders and other ways already existing in OSM, and delete the one with FIXME from your candidates, and use the existing state border as part of the new relation? The "import" upload should immediately be correct and not a broken state until post-import changes clean things up, it should be uploaded clean in the first instance. So this means manually working on it in JOSM before uploading. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] Admin levels for LGAs / suburbs etc changed (Was "Suburbs & admin boundaries stopping streets being found?)
Thanks! Graeme On Sun, 13 Sep 2020 at 16:52, Andrew Davidson wrote: > Looks OK to me. > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
