Two alternative approaches to the problem of converting radar signals into a form suitable for use in digital computers are considered and the problems discussed. One is automatic extraction and track production, and the other is manual, but based on the use of computer aids to enhance the operator's efficiency and reliability. Possible solutions are outlined and some difficulties which need to be overcome are explained.The two methods are then compared from the point of view of a potential user and it is shown that, when reasonably developed, each method has advantages. The relative advantages of the two approaches show up differently under different requirements and the choice must therefore be made in the light of a particular set of present and future requirements.It is also suggested that the choice is not always clear-cut. Automatic tracking systems may need human assistance in some circumstances and manual systems may be successively more assisted by a computer.