Abstract
This article presents an investigation which evaluates the effects of the action conducted by inter-ecclesiastical groups during the " Week for Peace " in the Netherlands. The author tried to see what real influence these annual campaigns had on public opinion and behavior. Three successive investigations in 1969 and 1970 permitted the measurement of: the degrees of implication of the actors of these groups ; the degree of participation of the public aimed at ; the degree of listening where action in the public arises ; the degree of accomplishment of the objectives fixed by those responsible for these actions. The combined investigations end in recommendations for better attainment of the objectives.