This article provides a detailed review of the ethnosurvey, a research methodology that has been widely applied to the study of migration for almost four decades. We focus on the application of ethnosurvey methods in Mexico and Poland, drawing on studies done in the former country since the early 1980s and, in the latter, since the early 1990s (including several post-2004 examples). The second case is particularly relevant for our analysis as it refers to a number of novel migration forms that have been identified in Central and Eastern Europe in the post-1989 transition period. Drawing on these studies, we consider the advantages and disadvantages of the ethnosurvey as a research tool for studying inter-national migration. Its advantages include its multilevel design, blend of qualitative and quantitative methods, reliance on retrospective life histories and multisited data collection strategy. These features yield a rich database that has enabled researchers to capture circular, irregular, short-term and se-quential movements. Its disadvantages primarily stem from its hybrid sampling strategy, which neces-sarily places limits on estimation and generalisability and on the technical challenges of parallel sampling in communities of both origin and destination. Here we argue that the ethnosurvey was never proposed and should not be taken as a universal methodology applicable in all circumstances. Rather it represents a specialised tool which, when correctly applied under the right conditions, can be ex-tremely useful in revealing the social and economic mechanisms that underlie human mobility, thus yielding a fuller understanding of international migration’s complex causes and diverse consequences in both sending and receiving societies.

A handful of studies have used Facebook’s advertisement platform – Facebook Ads Manager – to recruit migrants to online surveys. The main challenge facing migration scholars in designing effective advertisements has been to identify and accurately target migrants on Facebook. Researchers have used proxies, such as users’ previous residence abroad, language(s) or interests, to infer their migration status. Despite some progress, there remains a need to better document and reflect critically on the accuracy of targeting migrants using such proxies. Contrary to studies which relied on users’ previous residence abroad, this study used migrants’ language (Polish) to target and recruit survey participants from among Polish migrants in Norway, Sweden and the UK. Focusing on a single migrant group across three countries, the goal of this article is to assess the accuracy of a targeting strategy which relied primarily on users’ command of a language as an indicator of their migration background. Comparing the results against official migration statistics and the results reported in similar studies, the article provides a compelling case for researchers to prioritise users’ language, rather than previous residence abroad, as the proxy for migration background for migrants whose language, such as Polish, is confined to the borders of a single nation state.