One of the important prospects for the national information infrastructure is the wide-spread availability of on-line data and information services on a large scale. However, existing means of information access will not scale up to a network of this size. We believe that access to appropriate information, the ability to contact the right source at the right time, is the most significant obstacle to making a large-scale information infrastructure work. We see two significant consequences of having a large pool of information distributed over wide-area networks. First, information is placed in publicly-accessible locations by individuals or organizations who have a stake in seeing that the information is correct, useful and accessible. Second, the sheer size and distribution of these resources means that users will have difficulty knowing where to look for answers to specific questions.