Market studies done in a rural environment do not seem to present any particular methodological problems when the persons interviewed are "modern" i. e. culturally urbanised farmers who direct large modern farms, have mental attitudes comparable to those of an industrial entrepreneur or an urban consumer. But, there still exist in Europe, and particularly in France, rural populations which have been little permeated by the industrial and urban type of society. From a social psychological point of view, these farmers are still representative of traditional peasant societies. Their upbringing has, in large part, been determined by the specific conditions of the local community; their values, their cultural models, their ways of thought - the very nature of their intellectual processes are at variance with urban values, models, and types of reasoning. Therefore, the "peasant" tends to perceive the interviewer, who comes to ask him questions, as a "gentleman from town", a representative of the global society, and tends to react to his questions by playing the role of the peasant. His responses to a questionnaire may thus be over-accentuated by the characteristics of the interviewing situation and they may finally prove to be of little significance. The opinion questionnaire, itself, may appear as an instrument of investigation thoroughly inappropriate for certain categories of persons interviewed. Having been in a position over the last ten years to utilize various methods of research within and action on a rural environment, the author attempts to compare the advantages and disadvantages of these methods for the knowledge of "peasant" behaviour. Market studies in French rural areas have developed greatly over the last ten years. At the same time, research in rural sociology and economics, and efforts to compose more valid agricultural statistics are bringing a greater volume of useful information to specialists of surveys. But this field still poses numerous problems to those who work in it. We will try, in this paper, to discuss several of these problems.