OpenStreetMap

brittag's diary

Recent diary entries

A thing I learned about neighborhood names and Nominatim

Posted by brittag on 4 April 2015 in English (English)

Here's something I learned today, which might be interesting for other people working on mapping or on improving user experience for map editors.

I recently found that when I searched for Isla Vista Elementary School, its place name listing included "Ellwood" as the neighborhood, which is incorrect - the school is in the neighborhood of Isla Vista (as you can probably guess from the name), not in the nearby Ellwood neighborhood. I wanted to fix this, but I was confused about where this Ellwood place name was coming from - I couldn't find a tag on the school that mentioned Ellwood, and I couldn't find a boundary/border/area for Ellwood that included the school. Part of the weirdness to me is that Ellwood is in the city of Goleta, and Isla Vista is in unincorporated county land outside of Goleta.

Then I asked about this on #osm IRC, and a person explained that to figure out what's going on here, I could look up the school on Nominatim (which I hadn't heard of before other than seeing a mention of it in the search interface and didn't know what it was!), which said that Ellwood was a nearby node. Then #osm told me the next thing I needed to know: that Nominatim was probably using the Ellwood node as a guess for the neighborhood since it didn't have anything better, such as a closer node or an area.

Ah ha! So I put in a neighborhood node at the center of Isla Vista with the name "Isla Vista". Now if you search for Isla Vista Elementary School, the generated address includes "Isla Vista" in the place name listing. It now also includes "El Encanto Heights" though, since that's another nearby neighborhood node - which is incorrect as a place name for the school's area. So it looks like I'll need to figure out how to put in an area boundary for Isla Vista if I want this to be more reliably accurate.

(Update: OK, the school isn't showing El Encanto Heights anymore, but now it's showing "El Colegio Road, Isla Vista, Santa Barbara, Santa Barbara County" as if it's in the city of Santa Barbara, which isn't right either.)

Isla Vista is an unincorporated area (and census-designated place) that has its own identity but also a history of being accidentally assigned to nearby cities by people talking and writing about it (through ordinary confusion), so it's nice to help build a source of geographic information that provides accurate information about Isla Vista's relationship to nearby neighborhoods and cities.

Also, it might have helped reduce my confusion to see a tiny two-word explanation of Nominatim on the OSM search results page and a brief explanation on its homepage instead of having to click a small link to Documentation to get an overview of what "Nominatim" means. :) Now that I know what it means, I see that in its FAQ it has some information for "How was the address calculated?" and "How do I fix the address?"

Update on 13 April: I filed a suggestion for Nominatim to improve its site header and improved the advice for how to fix address problems, with the help of a person on the #osm-nominatim IRC channel. :)

Location: Isla Vista, Santa Barbara, Santa Barbara County, California, 93117, United States of America

New contributor experience

Posted by brittag on 6 August 2013 in English (English)

Writing this down since it may be useful for other beginners:

My biggest confusion at first was that my edits didn't show up right away, and the interface provided no hint about why that was happening (so I wondered if I was doing something wrong). I googled it and found out that delays are normal, but the estimate in the FAQ said "a few minutes", which hasn't seemed accurate for me - my edits often seem to take hours to show up. So I just have to do my edits and then check back on them later; as a newbie, it's important to me to verify my edits to make sure I did them correctly. Eventually I read the extended technical explanation for delays on the Q&A site, and it helped me be patient with the process; I'm not a programmer, but I work with software, and I can appreciate descriptions of complicated caching systems. :)

My next stumble was when I found editing a set of park boundaries difficult to do properly (since attempting to fix the boundaries seemed to delete the adjoining streets). I asked the OSM IRC channel for help (which I found by googling "OSM IRC", since I'm familiar with IRC and like using it), and their comments suggested trying a different editor - which worked! Fixing the boundaries was much easier in iD than in Potlatch (which I'd been using since it's the default editor), even though I've stuck with Potlatch for most edits since it provides lots of point-and-click options for adding and annotating points of interest and other details. I learned that if something is hard/tricky, I should try a different editor.

I only ran into the Good practice wiki page and Bing wiki page by accident (when trying to help an even-newer person on IRC), but they're very helpful. On the "good practice" page, "One feature, one OSM element" confirmed for me a best practice I'd guessed about, and I appreciated learning why it was OK to trace from Bing (I'd been wondering about that).

I'd heard about the Humanitarian OpenStreetMap Team a while back via people I follow on Twitter and via a presentation at OSCON about HFLOSS, and checking out the HOT OSM site turned out to be a good candidate for solving my current stumbling block of "what should I try next after fixing the obvious problems in my neighborhood?": the Tasking Manager - nice!

Postscript: I just noticed another issue - I'd had this New Diary Entry page open for several days while writing down notes, and finally I clicked "Preview" and confirmed that it looked good enough to post, but when I clicked "Save" I got an error message - I was no longer logged into OpenStreetMap! I would have lost my post text if I hadn't had a copy of it in a text editor. It would be nice for "Preview" to somehow check that the person is still logged in, to avoid losing posts.

Older Entries | Newer Entries