based PSI analysis and presentation, not just to crime mapping: 
In general, a map is just a map, not reality. It doesn't always and necessarily provide 
scientific evidence. Crime maps, for example, are NOT safety maps, as most citizens 
would, more or less consciously, like them to be: a tool that tells them where to buy a 
house their according to the level of criminality in the district. 
When used in that way, crime maps can give unprepared users two false impressions: 
the first, obvious one, is that certain areas are only criminal spaces, exclusively 
inhabited by criminals. The other is to encourage a purely egoistic vision of the city, 
where the need for safety becomes paranoia and intolerance and all that matters is to be 
inside some gated community. This doesn't lower crime levels at all: the only result is to 
increase urban segregation. 
To make things worse, crime data not analyzed and explained properly don't just contribute to  
strengthen egoistic attitudes and lock the urban areas that are actually the most plagued by crime  
into their current difficult state indefinitely. Sometimes, they may even perpetuate beliefs that are,  
at least in part, simply false. Of course, when those beliefs not grounded in facts already existed,  
open crime data can help, by finding and proving the gaps between perception of criminality and  
reality. Belleri, for example, notes that residents of Milan consider the outskirts of their city more  
dangerous than downtown Milan, while Londoners think the opposite about London... but in both  
cities the truth emerging from data is exactly the opposite (at least for certain categories of crime) of 
what their residents believe. 
3.6.3. Unequal access
Even  ignoring crime  mapping, in some  worst case  scenarios, data openness may be not only 
hindered by social divisions, but also create or enhance them. If citizens can't find and recognize  
real, relevant  meaning and practical value in data, as well as way to use them to make change  
happen, there won't be any widespread, long lasting benefit from openness. How can we guarantee,  
instead, that such meaning and value will be evident and usable? What are the ingredients for  
success here? 
Enhancing access to PSI it's harder than it may seem because it isn't just a matter of physical  
infrastructure.  It  is  necessary  that  those  who  access  Open  Data  are  in  a  position  to  actually 
understand them and use them in their own interest. 
This is far from granted also because, sometimes, the citizens who would benefit the most from  
certain data are just those, already poor, marginalized and/or without the right education, who have  
the least chances to actually discover and be able to use them. This is what G. Friedman was  
19/34
Copyright  2011 LEM, Scuola Superiore Sant'Anna. This work is released under a Creative Commons attribution license (http://creativecommons.org/licenses/by/3.0/)