We identify a problem with the process of research in the human-computer interaction (HCI) community-an overemphasis on "radical invention" at the price of achieving a common research focus. Without such a focus, it is difficult to build on previous work, to compare different interaction techniques objectively, and to make progress in developing theory. These problems at the research level have implications for practice, too; as researchers we often are unable to give principled design advice to builders of new systems. We propose that the HCI community try to achieve a common focus around the notion of reference tasks. We offer arguments for the advantages of this approach as well as consider potential difficulties. We explain how reference tasks have been highly effective in focusing research into information retrieval and speech recognition. We discuss what factors have to be considered in selecting HCI reference tasks and present an example reference task (for searching speech archives). This example illustrates the nature of reference tasks and points to the issues and problems involved in constructing and using them. We conclude with recommendations about what steps need to be taken to execute the reference task research agenda. This involves recommendations about both the technical research that needs to be done and changes in the way that the HCI research community operates. The technical research involves identification of important user tasks by systematic requirements gathering, definition and operationalization of reference tasks and evaluation metrics, and execution of task-based evaluation, along with judicious use of field trials. Perhaps more important, we have also suggested changes in community practice that HCI must adopt to make the reference tasks idea work. We must create forums for discussion of common tasks and methods by which people can compare systems and techniques. Only by doing this can the notion of reference tasks be integrated into the process of research and development, enabling the field to achieve the focus it desperately needs.