As part of the BBC launching thier new show called The Truth About Crime, they have launched a new "Crime Map" website that uses heatmaps to show real crime data for Oxford, England. The heatmaps are visual representations of all the crime data available for the 12-month period from November 2007 to November 2008.
The website is designed to allow users to explore crime patterns, discover more about potential risks and take action to prevent crime. The site features a specifically commissioned crime map of Oxford created with data supplied by the city's emergency services.
Why are you using heatmaps?
There are a number of methods for mapping crime. Currently, the technique most often used is to map crime data according to geographic areas such as postcodes, census output areas or police 'beat-codes'. The geographic areas chosen to map crime data – such as 'beat-codes' by the police – are often done so because these services deploy their resources according to their chosen geographical areas.
However, as these geographical areas vary greatly in size, when crime data is plotted on a map it is often difficult for a member of the general public to properly see and understand which areas have high or low crime rates. A large area may seem to have more crime than a small area even though this is simply because there is more space and people in that area. A small area with high crime might be hard to spot because it is simply physically smaller on the map, and therefore harder to see.
After extensive consultation with a host of experts in this specialist area, we have decided to use 'heatmaps' to display our crime data, since these offer a clear way for us all to see patterns of crime, without requiring us to have the expert knowledge of crime data analysts, nor a prior knowledge of arbitrary geographical areas. These 'heatmaps' represent the relative amount of crime according to a sliding scale of colour (as detailed in the "Key"), and provide a sense of the area where a type of crime is happening without disclosing the exact location that it took place – so as to protect the anonymity of victims
Heat maps such as these have not previously been used to any great extent in the UK, but have been used in the USA and Canada.