Reference service is defined as the mediation by a librarian between the need structures of users and the structures of information resources. The general process by which reference librarians accomplish this is outlined as including the phases of question clarification, question translation, search strategy formulation, search execution, delivery of information, and relevance evaluation. The impact of network development on each of these phases is discussed. The use of communications technology is viewed as a means for improving the interactive nature and response time of network reference service. Research into information and its use, as a basis for network reference service development, is urged. (Other papers from this conference are available as LI 003360 - 003367 and LI 003369 through LI 003390) (Author)