This paper results from cross-disciplinary reflection by social and biotechnical researchers engaged in surveys with experts from the agriculture and nature spheres: farmers: technical advisors, managers of nature conservation programmes and biologists. The purpose was to analyse the way professional knowledge is used by researchers to enrich their body of scientific knowledge. How professional knowledge is used depends in part on each scientific discipline, but far more on the final research aims. We first identified three ideotypes based on whether professional knowledge is used (1) in a comprehensive way to understand its origins, (2) to build new biological knowledge complementary to the one produced on an experimental basis, or (3) to build operational knowledge to help professionals manage their problems. A cross-analysis of the survey methods used then led to discussing the nature of the scientific knowledge developed from professional knowledge and the innovative potential of such surveys. Finally the heuristic potential of surveys is highlighted