Discusses some advantages of resource sharing through a network of computers as compared to resource sharing through other forms of time-sharing services. The ARPA network of computers, sponsored by the Defense Advanced Research Projects Agency of the Department of Defense, is used as an example of large-scale resource sharing in a computer network. The technical and economic aspects of computer networks are discussed, touching only briefly on legal and social implications. This paper describes some difficulties encountered in the use of computer networks and possible ways to address these difficulties. The problem areas discussed are those with application to a broad group of users, and with high potential for solution in the near future. 24 pp. Ref. Bibliog.