Although student-centred learning environments have recently attracted attention, such systems often place an unusual cognitive burden on the learner. Recent research suggests that cognitive tools can scaffold student-centred learning in these types of environments. This paper introduces and analyses problems and issues in the design and use of cognitive tools in student-centred learning environments and provides an overview of tool functions. A conceptual framework featuring functional cognitive tool classifications (information seeking, information presentation, knowledge organization, knowledge integration and knowledge generation) and principles of design is provided. Prospects and challenges for future research and development in the design and use of cognitive tools are also addressed. (Contains 1 table and 3 figures.)