What Works Centre: Q and A
What is the What Works Centre?
The What Works Centre for Crime reduction, within the College of Policing, was set up in
September 2013 to map the crime reduction research evidence and get this evidence used
in practice. It’s part of a world-leading network of What Works Centres launched by the
Cabinet Office to provide robust evidence to guide decision-making on public spending.
What is the Crime Reduction toolkit?
The College of Policing and the Economic and Social Research council have co-funded a
consortium led by University College London (UCL) to identify and label all the existing
reviews of research evidence on crime reduction interventions. The toolkit enables all the
results to be available in one place online and for users to weigh up evidence on impact,
cost and resourcing of different interventions and use this to help inform their crime reduction
efforts.
The toolkit is launching with only a few interventions. When will the remainder be
added?
Over 300 reviews have been identified, covering around 60 different crime reduction
interventions. These interventions will be added in batches, over time, to the What Works
Centre for Crime Reduction toolkit, hosted by the College of Policing.
We are launching with 14 interventions to begin with but it will grow as the existing review
evidence is added and we encourage research in areas where there are currently gaps in
the evidence base.
Can anyone submit a crime reduction intervention to put on the site?
The content on the site has been rigorously reviewed. All the interventions have been
subject of a systematic review, meaning the research must meet strict criteria to be included.
The results are then assessed across five areas in relation to both the evidence emerging
from the reviews and the quality of that evidence. The five areas include: the impact on
crime; how interventions work, where they work best, how to implement them and what they
cost.
The toolkit has helped us see where there are gaps in the evidence base and we are keen to
encourage further research development in those areas in the future.
Is the research only from the UK?
No. The reviews capture the best available evidence in the UK and internationally. Some of
the reviews reference studies in the US, Canada, Australia and Sweden.
What is the most effective intervention?
The toolkit helps users to see which interventions are effective in reducing crime, where
there is no effect and where interventions are harmful (i.e. increase crime), but it does not
rank these interventions against each other. Different interventions are effective in reducing
different crime types and will have varying levels of impact depending on the context in
which they are used. This makes it difficult to rank effective interventions against each other.
Of the interventions released on the toolkit today, five have been shown to reduce crime
these are: CCTV; street lighting; Neighbourhood Watch; sobriety check points; and alcohol
ignition interlocks.
What is the least effective?
The toolkit helps users to see which interventions are effective in reducing crime, and
identify those that are harmful (i.e. increase crime), but it does not rank these interventions
against each other. That said, of the interventions released on the toolkit today, Scared
Straight, which involves organised visits to prison facilities by juvenile delinquents or children
at risk of becoming delinquent has been found to not only be ineffective, but to actually
increase offending.
These programmes include confrontational ‘rap’ sessions in which adult inmates share
graphic stories about prison life with the juveniles. Other less confrontational methods and
more educational sessions include inmates sharing life stories and describing the choices
they made that led to imprisonment. The aim of these is to deter those at risk by showing
them the reality of incarceration.
However, the evidence suggests that the intervention has increased juvenile offending. In
most studies reviewed, on average, more juveniles who participated in the program were
found to commit offences, compared to juveniles who did not participate. This evidence
suggests a backfire effect of the programme. It is not clear why or how the programme
encourages offending behaviour in juveniles.
Looking at the evidence on electronic monitoring it would seem that it doesn’t have
any impact. If this is the case is the College saying offenders shouldn’t be monitored
anymore?
The review specifically looks at moderate to high-risk offenders. Electronic monitoring is
usually combined with other interventions aimed at desistence from crime, and evaluation
studies often examine the effectiveness for a period of time that extends beyond the
monitoring period. As the summary explains there are some sizeable gaps in the evidencebase which require more carefully designed studies.
If there’s such big gaps, then why include it?
The purpose of the Crime Reduction toolkit is to rate and rank the best available evidence
and to identify gaps. Where there are areas where the findings aren’t as strong, or we can’t
determine clearly how effective or ineffective something is then we will look to encourage
research in those areas to understand more about what does and doesn’t work.
There’s a lot said about CCTV being too intrusive and that there are too many of them.
What does the evidence about that?
There is evidence that CCTV modestly reduces crime overall. Overall, for every 100 crimes,
an average of 16 crimes were prevented with CCTV (based on 41 studies).
There is also strong evidence that it is particularly effective in reducing crime in car parks. In
looking at crime types specifically, the most significant reductions were for vehicle crime [for
every 100 crimes, an average of 26 crimes were prevented (based on 22 studies)] and there
was no evidence of an effect on violent crime. Implementing CCTV with wider coverage, and
in combination with other interventions, such as street lighting, can increase effectiveness.
This overview does not consider the effect of CCTV on detection, public order or other uses.
We’ve already seen stories of local councils looking to turn off street lights to save
money. Your findings would suggest that this is a bad idea?
Overall, the evidence suggests that improved street lighting can reduce crime. Crime (violent
and property) reduced by an average of 21% in treatment areas where street lighting was
increased, relative to comparison areas without increased street lighting. Exactly how this
effect is achieved remains currently unknown.
The evidence shows that increased police patrols have no impact on preventing
alcohol-impaired driving. Should chiefs withdraw their resources from roads policing
initiatives? The national policing lead yesterday was only calling for harsher penalties
for mobile phone use?
The overall review concluded that the existing evidence is insufficient to establish whether
increased police patrols consistently reduce the adverse outcomes of alcohol impaired
driving.
The evidence does not look at the use of mobile phones.
Are you surprised that Neighbourhood Watch schemes don’t work as effectively in
the UK as they do elsewhere?
There is evidence that Neighbourhood Watch modestly reduces crime overall. It appears
that it is more effective in the USA and Canada than it is in the UK. There is little evidence
on how it works in practice and schemes vary considerably in terms of coverage,
management, funding and initiation.
APPENDIX A
The effect scale
How we rate the effect of an intervention on reducing crime.
Effect rating
What it means
Overall, evidence suggests an increase in crime
Overall, evidence suggests an increase in crime (but some studies
suggest a decrease)
Overall, no evidence to suggest an impact on crime (but some studies
suggest an increase)
No evidence to suggest an impact on crime
Overall, evidence suggests no impact on crime (but some studies suggest
either an increase or a decrease)
Overall, evidence suggests no impact on crime (but some studies suggest
a decrease)
Overall, evidence suggests a decrease in crime (but some studies
suggest an increase)
Overall, evidence suggests a decrease in crime
The quality scale
Text to reflect specific review
Although the review was systematic, many forms of bias that could
influence the study conclusions remain
Although the review was systematic, some forms of bias that could
influence the study conclusions remain
The review was sufficiently systematic that many forms of bias that
could influence the study conclusions can be ruled out
The review was sufficiently systematic that most forms of bias that
could influence the study conclusions can be ruled out
Mechanism
No reference to theory - simple black box
General statement of assumed theory
Detailed description of theory - drawn from prior work
Full description of the theory of change and testable predictions
generated from it
Full description of the theory of change and robust analysis of
whether this is operating as expected
Moderator
No reference to relevant contextual conditions that may be necessary
Ad hoc description of possible relevant contextual conditions
Tests of the effects of contextual conditions defined post hoc using
variables that are at hand
Theoretically grounded description of relevant contextual conditions
Collection and analysis of relvant data relating to theoretically
grounded moderators and contexts
Implementation
No account of implementation or implementation challenges
Ad hoc comments on implementation or implementation challenges
Concerted efforts to document implementation or implementation
challenges
Evidence-based account of levels of implementation or
implementation challenges
Complete evidence-based account of implementation or
implementation challenges and specification of what would be
necessary for replication elsewhere
Economics
No mention of costs (and/or benefits)
Only direct or explicit costs (and/or benefits) estimated
Direct or explicit and indirect and implicit costs (and/or benefits)
estimated
Marginal or total or opportunity costs (and/or benefits) estimated
Marginal or total or opportunity costs (and/or benefits) by bearer (or
recipient) estimated