Defining Neighborhoods: Tricky Business
Last week, Zillow released boundary files for over 7,000 neighborhoods throughout the US. Previously Zillow had provided neighborhood demographic data via its GetDemographics API but had not provided boundary definitions of neighborhoods.
Defining neighborhoods is a tricky undertaking. I took a class in high school titled, ‘The Urbanization of San Francisco’. I clearly remember our first homework assignment. We were tasked to draw maps of our neighborhoods. People came to class with wildly diverse maps, in both detail and scale. Some folks thought of their neighborhoods as very small areas while others thought of their neighborhoods as much larger and less detailed. This exercise got us to examine our cognitives maps and how we think about the spaces we live in.
San Francisco’s SFGIS site provides two sets of neighborhood boundary files for the City, one from the San Francisco Association of Realtors and one from the Department of City Planning. As you might imagine, the realtors break the City down to many more neighborhoods than Department of City Planning does. By exploring Andrew’s mashup I realized that Zillow uses the Department of City Planning neighborhood boundary files instead of the San Francisco Association of Realtors boundary files. Here is a map of San Francisco’s Planning neighborhoods:
An example of a neighborhood missing from Zillow’s boundary files is Cow Hollow. Trulia divides San Francisco into the neighborhoods defined by the San Francisco Association of Realtors. This screenshot shows the Trulia boundaries for the Marina, Cow Hollow and Pacific Heights.
How do you define your neighborhood?