In modern post-Renaissance western society, museums are the political and cultural institutions entrusted with holding the material evidence, real things, which constitute much modern knowledge. The paper considers some aspects of museums as institutions holding this material evidence - the institutional relationship to accepted knowledge and value, the implication in the social and economic system and the visible architectural display, - which make up the messages which museums communicate to their visitors through exhibitions and interpretive projects. Three related aspects of interpretation which belong with each museum object and specimen are examined, professional care, interpretive approaches and the nature of collections. Finally, these threads are drawn together to suggest a framework of research and investigation which underpins the approach to our understanding of this aspect of the heritage, and points the way to future work.