A Randomized Experimental Study Of Sharing Crime Data With Citizens: Do Maps Produce More Fear?


Groff et al. (2005)


Although the dissemination of crime information is intended to benefit community members, there is a lack of empirical evidence demonstrating the effects of crime mapping on citizen perceptions and fear of crime. This experiment compared three formats for disseminating crime data; two popular types of crime maps (i.e., graduated symbol and density) and the traditional tabular format of crime statistics. A randomized experimental design was used to measure residents’ fear of crime and their perception of the safety of different areas of Redlands, CA.


Citizens were given crime statistics in three different formats: 1)A graduated symbol map, in which users are easily able to identify the number and type of specific crimes in particular areas using geometric symbols; 2) A Density map, where the shading on the map reflects the presence and severity of a crime (darker shades=more crime); or, 3) An orientation map and crime statistics for the same time period, not meant to convey crime on its own, but to provide context for the boundaries of an area in which a crime has been committed from the crime statistics table


1) In general, residents who viewed either the graduated symbol or density maps reported less fear than those who viewed tabular statistics.

2) Respondents who viewed graduated symbol maps consistently reported less fear than either density maps or tabular statistics.

3) Finally, the maps did not appear to stigmatize high crime areas of Redlands. Where statistically significant differences existed, respondents who were given graduated symbol and density maps were more likely to recommend someone move into an area than those who were given tabular statistics.

Full document here

#Crime #Perception #Trust #Randomizedcontrolledtrial

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