How does the researcher make judgements about the validity of his or her data? This is a question relevant for all research, but offers a particular challenge for naturalistic research inquiry. The authors map out the particular problems and opportunities presented by observational research

In this article, we look at validity in observational research, paying particular attention to 'triangulation' as a research strategy which can enhance validity. We describe the types and purpose of triangulation and draw from a study which illustrates how triangulation can be used. As an illustration of one type of triangulation, we explore how participant observers can validate their observations using ‘respondent validation’, in which the participants reflect on and validate the researcher’s accounts. We look at the advantages and limitations of respondent validation and also what we see to be the limitations, strengths and challenges of triangulation.