The last decade has brought considerable progress in our understanding of how institutions like museums affect people's lives. However, there is still a great deal we do not know, and the research challenges ahead sometimes appear quite daunting. In this paper, we suggest that three characteristics of learning, its personal nature, that it is contextualized, and that it takes time, are critical to understanding and investigating the impact that museums have on people's lives. These characteristics have long been recognized, and we believe that recent research has emphasized their importance, but they are yet to be consistently well addressed in research. In the paper, each characteristic is elaborated and its implications for research examined. In particular, we argue that a search for a wider range of learning outcomes, the use of a wider range of research methods, and a greater consideration for, and recognition of, the significance of time are the principles for the future research agenda. © 2004 Wiley Periodicals, Inc. Sci Ed88(Suppl. 1):S4–S16, 2004