1. Some mySociety GIS thoughts
Chris Lightfoot
Matthew Somerville

2. mySociety builds websites which give people simple, tangible benefits in the civic and community aspects of their lives

5. Putting people in touch with their elected representatives
MPs, councillors etc. elected on geographic boundaries
Lookup of location to electoral geographies, via postcode
You can buy a data set that claims to do this, but it doesn’t
Instead need to get digitised boundaries of electoral geographies and intersect postcode coordinates with them

6. Putting people in touch with their elected representatives (2)
Even that is oversimplifying
Data availability...

7. A global gazetteer
Originally built for PledgeBank, but useful elsewhere
Application is locating people without requiring them to click maps or otherwise supply coordinates
Original data set is GEONet Names Server, compiled by the US military for their own purposes
“Why are there so many names for places in Russia?”
Plus USGS’s database of US place names

8. A global gazetteer (2) First application of this was for PledgeBank
Want to be able to create local alerts: “ me when a pledge is created near me”
We got a lot of whinging from Londoners complaining that we’d sent them mail about a pledge that was ten miles away
Solution: change definition of proximity
People in cities think about places a mile away being “nearby”
In rural areas they might think of the nearest town being “nearby”
etc.

9. Customary proximity
Idea is to use population density to compute threshold distance
In practice “within a radius containing about 200,000 people” seems to be a reasonable definition of “nearby”

10. Examples Islington, London 2.7km central Cambridge 15km mid-Wales 38km
Central Park, Manhattan, NY
1.8km

11. Where does the data come from?
Two global population data sets:
Gridded Population of the World Columbia University
Free, more-or-less
Based on census returns
Good in developed countries, less good elsewhere
LandScan Oak Ridge National Laboratory
Stupid licence fees
Incorporates, inter alia, regressions against night-time light density to infer population distribution within censal units
Higher resolution than GPW

12. A couple of “classic” Google Maps mash-ups

17. And a couple of others which aren’t actually mySociety projects but may be of interest here