Hidden populations have often been omitted from the social research due to difficulties in acquiring adequate information on and from them. Members of these populations are often elusive and difficult to trace as a result of their common stigmatization, ostracism or illicit nature.
The main aim of this paper is to discuss the methodological particularities encountered while studying hidden or hard-to-reach populations, the limitations of the traditional research practices and the possibilities of contemporary research in this field. In the first part of the paper, typical features of hidden populations are displayed, utilising the non-heterosexual population as typical hidden population.
For the reason that research on hidden populations has to deal with methodological obstacles in particular with problems connected to accessing the desired population, sampling bias and subsequently with the validity of collected data, methodological discussion is detailed. The second part of the paper scrutinizes chain referral sampling method, specifically a snowball method with attention aimed precisely at the method's utility for studying hidden populations, the application of a social networking and its practical online potential.
Various ways of countering typical snowballing errors, mainly sampling biases, are presented. In the last part of the paper, the experiences of other authors are discussed and reflected in the author's own case research design inspired by a snowball methodology conducted on Czech non-heterosexual population.
Evidence of applicability on the grounds of both quantitative and qualitative data is provided to demonstrate the definite qualities of using a snowball method in the field of hidden population research.