The word "knowledge" is associated with what we learn in school classes, but apart from such knowledge, farmers' experiential knowledge, which they acquire through their daily experiences, is called "farmer knowledge." To date, many technologies that are supposed to make sustainable agriculture possible have been disseminated in Africa, but there is a problem that farmers do not use them or stop using them soon after they are used. One possible solution to this problem is to understand "farmer knowledge. If we researchers can understand what farmers value and what they consider difficult in their daily farm work, and how they understand the characteristics of the soil and crops, we believe it will be possible to develop technologies that meet farmers' wishes and disseminate technologies in a way that is easily accepted by farmers.

The work of development economists is sometimes compared to that of a doctor. This is because it is like writing a "prescription" for poverty reduction. Indeed, the process of listening to farmers (i.e., interviewing), conducting surveys (i.e., medical examination), and suggesting ways to improve their lives (i.e., writing prescriptions) may be similar to the work of a doctor. However, farmers do not come to us for consultation (=see the doctor). I would like to talk about the deeper reason why we go all the way to the field to listen to the farmers.