Sampling and civil society engagement in surveying hard to reach populations

‘Hard-to-reach’ is a term used to describe sub-groups of the population that may be difficult to reach or involve in research and social statistics. Examples include LGBT+ people, irregular migrants, homeless people and more in general those living in vulnerable social and economic situation and people at risk of discrimination. Invisibility and cumulative disadvantages may characterize hard-to-reach populations. These groups are difficult to identify and recruit, and their sampling frames are usually unavailable. Moreover, official statistics need to gather data that can help to design and monitor policies to combat inequalities, discrimination and disadvantages. The National Statistical Institute of Italy has a long tradition on investigating different hard-to-reach groups. This paper critically analyses these different experiences, focusing on two main aspects: a) sampling techniques and b) civil society involvement. Strengths and limitations, as well as future prospects are discussed.