[Talk-us] Differences with USA admin_level tagging

[Minh Nguyen]

On 08/07/2017 12:32, OSM Volunteer stevea wrote:
> Kind of long and complex ahead; apologies in advance for the length.
> 
> I've been documenting our https://wiki.openstreetmap.org/wiki/United_States_admin_level wiki over much of the last year with careful research on how US states and territories carve themselves up into administrative subdivisions.  My thrust has been how states actually do this via their state constitutions, state legislation, real-world practice and in some cases on-the-ground signage (e.g. city limit or township boundary signs).  Research indicates minor differences in the way that the US Census bureau does something quite similar, and as noted in that wiki, OSM largely aligns, but there are minor exceptions (e.g. census boundaries in Alaska may be valuable enough to keep, but let's not call them administrative boundaries, they are not, but it's OK if the Census Bureau does so if we note that minor difference and tag in a way we discuss and document).
> 
> Whether those results (that wiki and its necessarily complex table and Notes) are fortunate or unfortunate, this prompted another OSM mapper (Minh Nguyen, he has kindly given me implicit permission to name him and explicit permission to cite his recent WikiProject addition) to create "his" https://wiki.openstreetmap.org/wiki/WikiProject_United_States/Boundaries wiki.  Minh's thrust there has been to carefully document what admin_level tags OSM actually DOES HAVE.  Even if those tags are "incorrect" in some legal sense, he documents what actually IS in the map.  OK, fine:  that is a noble goal and he has largely achieved it with this wiki in short order.
> 
> Without going through the sausage-making details of the flurry of our recent dialog (in wiki, talk-pages and private email exchanges), I am taking Minh up on his offer to "propose a change on the mailing list. Rally the OSM community behind your cause. You can even hold up the WikiProject United States/Boundaries page as a testament to how incorrect the map is right now."  (I quote Minh exactly there).  By doing so, I hope to generate more light than heat, essentially harmonizing both of our efforts and as a result, significantly improving our map.  Perhaps along the way, we hopefully better clarify what we mean by consensus:  what "the People" say via law and practice and what "we actually do in OSM as we put data into our map."  These are not and should not be fundamentally disharmonious, but the distinction seems to have created some friction I'd like to "solve."

Thank you for starting this discussion, Steve. I hope looping in the 
community will get us past the impasse that occurred in private e-mail. 
Whatever the outcome, I hope it'll result in a more accurate wiki. After 
all, the wiki works best when its pages closely reflect the state of the 
map, tagging proposals are clearly marked as such, and retagging 
proposals come with a gameplan. (The wiki has a reputation of being a 
blue-sky wishlist among some software developers, but I'd like to change 
that.)

Just to avoid misunderstanding: the quotes are around "his" because I 
don't own the "WikiProject United States/Boundaries" page, I merely 
wrote the first draft. It and "United States admin level" are two 
different wiki pages with different goals, but anyone can contribute 
towards those goals.

> Briefly (re-)stated, Minh characterizes this dichotomy as "prescriptive vs. descriptive."  In other words, Minh and I both claim the US_admin_level wiki prescribes how we SHOULD tag admin_level in the USA and the US/Boundaries wiki describes how OSM now DOES map them.  Our dialog has allowed me to identify specific differences, what appear to be deficiencies in our map, actually.  These are limited to nine US states (eight with deficiencies, a ninth with what appears to be a deficiency and perhaps an "off-by-one" error).  I now list these issues.
> 
> Here are what exist in state constitutions/statutes/the real world, map well onto OSM's admin_level scheme, yet do not exist in OSM's data:
> 
> Rhode Island 7/Town, 9/Village:  all are marked as 8/City when perhaps some are 7/Town or 9/Village
> Massachusetts 7/Town:  all are marked as 8/City when perhaps some are 7/Town
> Maine 6/Unorganized territory and 6/(unincorporated) Plantation
> Vermont 8/Village:  all are marked as 8/City when perhaps there are 9/Villages in some 8/Cities
> Pennsylvania 7/Township, 7/Borough are missing throughout, 8/Town subordinates to Borough, 8/Village and 8/Hamlet both subordinate to 7/Township
> Connecticut 6/Region (not County), or both?  Harmonize these
> Minnesota 7/Township, 7/Town (it appears simply that none have been entered)
> Illinois 7/Township, 7/Precinct?
> 
> New Hampshire, 8/Town:  shouldn't these be 7/Town (as inTownship)?  Are there 7/Organized Locations?

I want to call attention to three additional regions, beyond the nine 
Steve listed, because they were the subject of drive-by edits.

In the couple days since he and I last exchanged e-mails, Steve has made 
the following systematic changes to the map, along with corresponding 
edits to "WikiProject United States/Boundaries" to more closely match 
"United States admin level" [1]:

* Removed the admin_level=6 tag from Rhode Island's counties, leaving 
boundary=administrative in place:

http://www.openstreetmap.org/changeset/50107085
http://www.openstreetmap.org/changeset/50107160
http://www.openstreetmap.org/changeset/50107182
http://www.openstreetmap.org/changeset/50107200
http://www.openstreetmap.org/changeset/50107218

This confuses Nominatim, which continues to respect the county 
boundaries but assumes admin_level=15. [2] The openstreetmap-carto 
renderer no longer displays these boundaries, but it's possible that 
some renderers draw admin_level-less boundaries as solid lines, as 
openstreetmap-carto used to.

* Moved American Samoa's counties from admin_level=6 to 7:

http://www.openstreetmap.org/changeset/50121874

* Added American Samoa's districts to admin_level=6 where counties used 
to be (only in the wiki)

* Moved Guam's villages from admin_level=8 to 6:

http://www.openstreetmap.org/changeset/50122576

They may well be the right edits to make, but mappers who focus on these 
regions deserve a heads-up and an opportunity to agree or disagree.

[1] 
https://wiki.openstreetmap.org/w/index.php?title=WikiProject_United_States%2FBoundaries&type=revision&diff=1489329&oldid=1488779
[2] http://nominatim.openstreetmap.org/details.php?place_id=496879

-- 
minh at nguyen.cincinnati.oh.us