Number crunching: the methodology behind the figures
THE IRISH TIMES crime series, which begins today and runs through next week, is an in-depth analysis of Central Statistics Office (CSO) crime statistics that give a detailed breakdown of recorded offences for every Garda station.
The data covers offences registered in each of Ireland’s 704 Garda stations over an eight-year period between 2003 and
2011, including the 39 stations that were closed earlier this year.
The CSO releases crime statistics on a quarterly and annual basis but this data isusually at a macro level, providing for a breakdown of crimes nationally and at the level of the 29 Garda divisions. The station-by-station information on which this series is based, by contrast, allows for analysis at a micro level in each and every Garda station in the country.
Comparing crime statistics over time and across regions is not straightforward. Published statistics only include crimes that become known to or are reported to gardaí. Whether a crime comes to their attention depends on various factors including the “perceived seriousness (by the victim) of the crime, the financial loss involved and beliefs around whether the gardaí are in a position to do anything about the crime”, the CSO has stated.
The picture is further complicated by recent station closures and the fact that geographical catchment areas covered by some stations and Garda divisions have changed over the last 10 years. The Garda’s policing priorities also have an
influence on how many incidents of each type of crime are detected. Justin Gleeson of the NUI Maynooth-based All-Island Research Observatory (Airo) says that although there are many challenges in properly interpreting crime
statistics, this station-by-station breakdown helps to make crime data more accessible.
“This is an important step towards a more transparent process whereby members of the public, researchers and policy-makers can get a better understanding of the patterns that exist,” he says. “Publicly available crime data, as
long as it’s broad enough not to cause confidentiality issues, is standard practice in most countries and it's pretty much taken for granted that citizens can view key information like this to understand what's happening in local areas.”
Ireland is still “a long way off other countries such as the US and UK. In the absence of a postcode system in Ireland, crime data is still linked to the station it's recorded at. This causes problems and dumbs down the data; rather than knowing what's actually happening in, say, a large housing estate or a particular street, we just get the figures recorded for the overall station catchment.
“It still gives you a general sense of the patterns that are in place across the country.”
Airo is part of the National Institute of Regional and Spatial Analysis (NIRSA), an interactive spatial data portal that “aims to make information and data as transparent as possible through mapping and data visualisation tools to the public, planners and policy makers using free-to-use interactive graphs and maps.”