← Back to News
news

May 3, 2018

Announcing our first Evidence and Gap Map on homelessness

Dr Lígia Teixeira

Currently there are no reliable tools to help us identify what we know and what we don’t when it comes to reducing homelessness. Evidence is scattered around different databases, journals, websites, in grey literature – and there is no way for decision makers to get a quick overview of the existing evidence base. It also makes it hard for research funders to ensure that limited resources are spent effectively.


To address these issues, we have been working with the Campbell Collaboration, Heriot-Watt University and Queen’s University Belfast to produce Evidence and Gap Maps (EGMs) that capture the big picture of effectiveness studies from across the globe so we can better understand what we know and don’t know about the impact of homelessness interventions. EGMs provide quick and efficient tools to highlight what evidence exists for specific interventions and outcomes so as to make it accessible for decision-makers and those investing in research. They can be easily explored and also include links to study synopsis.

Today we release our first EGM that focuses on the most reliable evidence available about what works, impact evaluations and systematic reviews. 

We encourage you to try the map out for yourself.


The report that accompanies the first map provides an introduction to EGMs, outlines the gap-map methodology and presents insights from the work. The map shows that very few high-quality evaluations exist in the UK despite the significant number of resources devoted to evaluation each year.

Explore our report

It’s not all bad news. We found that there has been an increase in the number of rigorous studies in recent years. Prior to 2000, there were just under two studies a year published, an average of four a year from 2000 to 2009 and since 2010 nearly 10 a year. Also, the map is not a desert – with the exception of legislation, there are studies we can learn from in most outcome areas. The largest concentrations of studies are on health and social care interventions, followed by accommodation-based approaches. There are far fewer studies addressing employment and income or education for those at risk of homelessness. By highlighting such gaps, we can infer where future funding might be directed.

Our first map shows there is an evidence base on which to build an infrastructure for evidence-based policies – but there are some important caveats. The vast majority of the evidence is from North America – only 11 studies are from the UK and most of these are from London. International studies are useful but differences in context may mean that approaches that worked elsewhere work less well, or better, here. It is therefore vital that local studies of promising interventions are carried out.

For researchers, decision makers, practitioners and funders alike, these are a strategic starting point for looking at investments in the production and use of evidence. For lasting change to happen, before we intervene in people’s lives we need to consider the best available evidence of what works and what does not or risk wasting opportunities and doing harm. Because EGMs highlight the quality of evidence, policymakers can make an informed judgement about what is credible and rigorous research.

In collaboration with our network, we will be pursuing a programme of action to fill gaps in the evidence so that over time the maps come to be used as a standard reference for evidence creation and use. We are now building on the work done towards the EGM by producing overviews for the first version of the Centre’s intervention tool along the lines of those produced by the What Works Network in the UK and the What Works Clearinghouses in the United States.

In an age of increasing accountability and rationed research money, improving the targeting of funding and research to help ensure effective homelessness policies and interventions is more important than ever. 


Although funding commitments are important, simply throwing more money at this complex and multifaceted problem is unlikely to create lasting change. Using evidence more effectively will help to achieve better results. We hope that this report and related digital tools – and our annual sequels – will make a significant contribution to the dialogue and decision making on homelessness in years to come and lead to more strategic use of, and greater investment in, evidence.

← Back to News