User-computer interaction employing block mode data transfer

The use of a video display terminal (VDT) with "block mode" option can provide a natural transition from paper forms. The interaction of a user with a VDT-form is outlined in relation to a patient's data and the functions of data entry, display, update, and deletion. The invocation of a function is kept simple with the use of abreviations as command words and the requirement of a command word as the first element sent to the computer. The strong points include: 1) a simple approach for the user, 2) a process can be aborted at any point, and 3) functions that can be used are displayed at all times. The weak points are: 1) software interface problems and 2) terminal cost. Block mode is discussed in relation to a modular approach and a distributive system.