Distinguishing surveillance from research

The public health practitioner's, researcher's and administrator's search for a clear, concise distinction between what is meant by 'surveillance' and what is meant by 'research' never seems to be satisfactorily resolved, resulting in the notion of a 'grey area' where the respective activities supposedly cannot be differentiated. We investigate, from basic principles, why two seemingly straightforward concepts are so often confused and offer a conceptual framework which distinguishes health surveillance from other kinds of health-related investigation. Finally, we discuss the policy and practice implications of failing to maintain the research/surveillance distinction.