The paper explores the nature of docents' work in museums. From this is derived the concept of the docent function to describe different aspects of that work, some of which may be performed by other people and also by objects such as maps and guidebooks. This analysis leads to the idea of the Cyberdocent – an extension of the docent function to take advantage of new possibilities afforded by advanced technologies. The potential of the Cyberdocent in both virtual and real museums is investigated. The authors claim that it is the provision of docent functions that make a physical museum more than merely a collection, and equally, it is by the provision of Cyberdocent functionality that a virtual collection becomes a virtual museum.