Thus a firm 'producing' marketing studies from survey data tries to control all of the different phases: conceptualization, fieldwork, data processing and interpretation of the final results. Our goal here is to study the question of the data processing phase in relation to different solutions to the problem. Before presenting a historical review we would like to outline the basic steps in processing survey data by defining their main characteristics. Naturally, we cannot undertake a full study of electronic equipment currently being used by marketing firms. Rather we shall talk from our own experiences to illustrate the evolution which has taken place in equipment and in the opening of new perspectives to users.