This paper discusses two related questions: Are research results usable? Are the data actually used in decision-making? Both are determined by the researcher's choice of research methodology. The links between choice of research methodology and the application of results is discussed through a simple conceptual model. A satisfactory link requires a decision to allocate part of research capacity to the evaluation of previous research. To demonstrate the difficulties involved in rigorous analysis, a case study of ten years of research for agricultural development in three East African countries (Uganda, Kenya, Tanzania) is reviewed. Deficiencies in agricultural planning and in applied research for agricultural development are discussed in detail. The causes of ineffective applied research are viewed as lying in scientific culture. An example of applied research with implemented solutions is given, emphasising the benefits of participant research and management procedures for planning.