Keeping Count

14 Oct 2008 by Rob Schafer

Tracking Multiple Incidents

Placing pins on a map is a simple and easily-understood way to relate an incident to its surroundings but this approach has can break down when the number of incidents in a given area increases. One problem I’ve encountered is that multiple pins placed in the same location obscure each other, causing the map to appear to contain fewer incidents than it actually does.

As of today the site now handles multiple incidents at an address by placing a single large grey pin on the address; clicking on the pin will show all of the events in a ‘tabbed’ popup window. This works best in for maps that contain a large number of incidents:

All reported incidents in the French Quarter

Data Fidelity

Viewing incidents in this fashion reveals that many incidents are reported more than once; for instance, in this view of Adams Street it seems obvious to me that the two incidents at Adams & Hampson St are duplicates. One was reported on September 25 and the other on September 27. As of today 458 of the 4,993 incidents in the Crime Watch New Orleans database appear to be duplicates. For now I am displaying them as reported but I plan to flag or remove them entirely at some point.