On the 14th and 15th of January, 1971, a workshop on The User Interface for Interactive Search of Bibliographic Data Bases was held in Palo Alto. The participants were provided in advance with a challenge paper and with a number of papers prepared in response to that challenge. The Workshop sessions themselves were devoted exclusively to focussed discussions of the material and of the problems in and the prospects for more effective systems design of the user interface. In recent years a number of computer-based systems involving on-line, interactive interrogation of bibliographic data files have been implemented, and several are in active use, serving a broad and varied clientele. However, discussions of these systems have tended to emphasize details of implementation or descriptions of the particular application involved. Although systems designers certainly have been concerned with making their systems easy to use, prior to this Workshop there has been no attempt to evaluate the accumulating experience about what happens "in front of the terminal" during interactive search. Consequently, this Proceedings constitutes the first statement of our current knowledge about the user/computer interface from the user's perspective. (Author/SJ)