The papers presented at the 18th Clinic on Library Applications of Data Processing discuss current developments and applications of new technologies for processing, transmitting, and storing information, as well as some issues raised by these new technologies. Ten papers are included: (1) a keynote speech on the changing roles of the information professional based on evolving information technology; (2) a tutorial on microcomputers; (3) a delineation of microcomputer applications in technical processing, public services, and management activities of libraries; (4) a description of the many applications of word processing at the U.S. Department of Agriculture's (USDA) Technical Information Systems (TIS) unit; (5) a survey of currently available data entry and display devices; (6) a discussion of U.S. and international projects which are testing the market for videotex and teletext systems; (7) an examination of recent developments in telecommunications, including electronic mail, facsimile, two-way cable, and digital telephones; (8) an outline of the basic characteristics of videodiscs as a storage medium; (9) an analysis of copyright protection for computer software and databases; and (10) an exploration of the relationship between technological change and professional identity. Brief descriptions of contributors and a subject index are provided. (Author/ESR)