In educational, developmental as well as cognitive psychology several approaches to measure epistemological beliefs have evolved. These approaches focus on learners' and teachers' beliefs about knowledge and epistemological issues. Such beliefs are important because of their impact on learning processes and learning results. Some of the most research approaches and their methods are outlined. Then some difficulties which the research is encountering are discussed. One of such difficulties concerns the issue of domain specificity of epistemological beliefs. This issue is one of the reasons for inconsistent empirical results. It will be suggested that some of these inconsistencies are caused by the epistemology implied in the research approach itself. In particular, the idea that epistemological beliefs can refer to knowledge as a social and cultural entity, is underrated. The paper concludes with the discussion of this argument and of it's consequences for further research.