Abstract. The measurement of knowledge transfer is considered an important component of the overall performance assessment of research groups. It is, however, not a trivial task, because there is agreement on neither the definition nor on the logical structure of knowledge. In this paper the problems related to the explication of the title term are summarized and the relation between knowledge and information is critically discussed. Open questions with respect to the logical structure of knowledge and its transfer are identified. Requirements to the concept of a knowledge transferometer are developed. Finally the request to scientests to measure their knowledge transfer is critically discussed.