The question of making digital computers more useful to technical personnel like engineers and scientists is discussed informally. It is suggested that computing systems should be designed for a type of use described as 'step-display-look.' It is also suggested that once the user has been put on-line, the problem of software becomes critical. In particular, the clerical labor that is usually required in instructing the computer becomes an important obstacle to rapid interaction between man and machine. The requirements for an experimental system intended to put these opinions into practice are sketched, and some of the major decisions that have been made in planning such a system are discussed briefly.