Improve zip / low accuracy behavior or messaging

[nickoneill]

Accepting zips as location is important for simplicity; folks like to have a low-PII way to provide their location. However, zips don't map to congressional districts in all cases and our mapping just uses the district that the "center" of a zip (as determined by google maps API) lands in.

We could do a better job of communicating when this happens, in some or all cases. Some ideas:

• Process all zip polygons and find out exactly which ones map perfectly to congressional districts and which ones are ambiguous
• When we detect a zip used as a location input (or just an ambiguous zip if we do the above step), present a message in the location picker that indicates this is an estimate only. Perhaps users can preview the house rep that we detected and if they know it's wrong, use an address? or pick from a list of reps? I don't expect many people will know exactly who to pick, so I don't really want to put the effort back on the user.

[heathermh]

I like the idea of having a message that this is an estimate (especially if it only shows for ambiguous zip codes). I'd like users to be able to test drive the app without committing to providing personal info. Then make it as easy as possible to update/correct once they decide they'd like to use the app for real.

Do you have a feel for what percentage of zip codes are ambiguous?

[nickoneill]

I have not run the numbers on the spatial data we have, but a number of years ago I read that 30% of zips are split. But some of those will return correct districts, some of those are probably very low population zips and that's before the more recent 2020 redistricting, so it's hard to tell how much it impacts folks in reality.

I captured details here because I was thinking about it but it's not something I want to focus on for the initial 2.0 release.