The form of the articles about the DIS developments published between April and September 1971 seemed quite obvious to those of us in BOAC and ICL who had been associated with interactive skills training in the preceding years. The sequence of articles in ICT was based on the historical and logical progression of concepts and activities from a review of available training, through to the behaviour survey and on the framework of the courses. A notable absence, which we hope to remedy in this article, is a detailed description of the way in which the behavioural data is processed. Apart from describing the system as used in BOAC some alternative methods are described. In particular a system which has been developed in Denmark, using a telephone terminal, appears to have advantages over the other methods available.