The Office of Technology Assessment is conducting an assessment of the effects of new information technologies--including high performance computing, data networking, and mass data archiving--on research and development. This paper offers a view of the issues and their implications for current discussions about Federal supercomputer initiatives and legislative initiatives concerning a national data communication network. The observations to date emphasize the critical importance of advanced information technology to research and development in the United States, the interconnection of these telecommunications technologies into a national system program, and the need for immediate and coordinated federal action to bring into being an advanced information technology infrastructure to support U.S. research, engineering, and education. High performance computers are discussed in detail using the Cornell Theory Center, the National Center for Supercomputing Applications, the Pittsburgh Supercomputing Center, the San Diego Supercomputer Center, and the John von Neumann National Supercomputer Center as examples. Several high performance computer facilities at the state level are also reviewed, as well as changes in the scientific computing environment, the review and renewal of the National Science Foundation (NSF) Centers, and international programs in Japan and Europe. A detailed discussion of the status of and policy issues surrounding data networking for science focused on the proposed National Research and Education Network (NREN) concludes the document. A list of reviewers and the names and affiliations of the High Performance Computing and Networking for Science Advisory Panel are included. (DB)