Hard-to-Reach Populations Research Methods is an international platform dedicated to advancing research and data collection methods with hidden, marginalised, excluded, and underrepresented populations.

Across the world, millions of people remain statistically invisible — not because they do not exist, but because traditional research methods often fail to reach them. Migrants, refugees, homeless people, displaced populations, victims of violence, informal workers, children in vulnerable situations, people living in conflict settings, and other marginalised groups are frequently absent from official statistics, research, and policy discussions.

Our work focuses on the methodological, ethical, and practical challenges of conducting rigorous research in these contexts.

The initiative brings together academics, statisticians, practitioners, policymakers, humanitarian actors, and students interested in improving how data are collected, interpreted, and used to inform policy and action. We promote interdisciplinary collaboration and encourage approaches that combine quantitative and qualitative methods, participatory research, innovative sampling strategies, geospatial tools, digital technologies, and community-centred approaches.

The platform is linked to the annual international conference and training programme on Applied Research Methods with Hidden, Marginal and Excluded Populations, organised in collaboration with UNICEF and University of Oxford. These activities create a space for methodological exchange between researchers and practitioners working in complex and often difficult operational environments.

We believe that better methods lead to better evidence — and that better evidence is essential for more inclusive policies, stronger accountability, and greater visibility for populations that are too often ignored.

Hard-to-reach populations are not impossible to study. They require different questions, different methods, different partnerships, and a stronger commitment to proximity, ethics, and trust.

You can also join our LinkedIn community to receive updates on conferences, training opportunities, publications, and discussions on research methods with hard-to-reach populations: Hard-to-Reach Populations Research Methods LinkedIn Group.