The purpose of this lecture is to give an impression of the possibilities which are open to the magazine publisher through the use of computer-models. They are pieces of electronic equipment which give the publisher a chance of seeing how his magazine will react under various circumstances as regards economy, circulation and the market. The aim of the lecture is not to give a technical explanation of the functioning of a computer, it is only the aim to give the listener an impression of the fact that the computer can be a valuable tool for the publisher in a decade in which the rapidly changing influences from within and without require ever new decisions and new reactions. These must be based on a first-class comprehensive view of the operation. This view can be secured by the computer-model, and the lecturer mentions a concrete example of a magazine which it was only possible to launch because a computer was used.