Having chosen a computer-assisted diagnostic system (ADM) based on a logic method of the documentation type, a real example of a questionnaire is presented. The procedures actually utilized as well as those now being studied are presented and discussed in the light of the difficulties encountered. After giving various detailed examples, the fundamental procedures in developing the computer-assisted diagnostic system are described. These have been developed keeping in mind that the system must preserve utility, feasibility, transparency, simplicity, liberty of choice and scope but must also handle all difficulties and causes of error that are inherent in the process of arriving at a medical diagnosis.