Data produced by the most recent survey conducted in 2011 provided a comprehensive Roma poverty picture from a human development perspective for countries in the Eastern part of Europe (Ivanov, Kling, and Kagin, 2012). This survey was also conducted by EU-FRA for 11 EU member states, providing comparable data. In addition to these groups (who are typically absent from the sampling frameworks for household surveys in most countries), there are also groups who, while in theory are included within the surveyed populations, are often very difficult to reach, leading to their under-coverage in official statistics.