Röling, N.G.Hounkonnou, D.Offel, S.K.Tossou, R.Van Huis, A.2019-03-182019-03-182004-12Vol 52, No 3-4, p. 211 - 235http://library.wur.nl/WebQuery...http://ugspace.ug.edu.gh/handle/123456789/28661The article is an introduction to a series of articles about diagnostic studies carried out by eight PhD students in Ghana and Benin. These studies form a prelude to their experimental action research with groups of farmers to develop technologies that work in local conditions and are acceptable to farmers. A last article reports on a comparison of these eight studies by the ninth PhD student in the Convergence of Sciences (CoS) project. In this introductory article, it is argued that the need to ground agricultural research in the needs and circumstances of farmers is as strong as the need to ground research in the international scientific discourse. It explores the reasons why the West African context requires careful diagnostic studies to be able to design agricultural research that is of any use. It introduces pre-analytical choice as an overriding concept to explain why choices that reduce the degrees of freedom have to be made explicitly on the basis of criteria. Such criteria are suggested for the quality of pre-analytical choices, and the paper ends by examining the way the CoS project made some of its choices.enAgricultural innovationDiagnostic studyPre-analytic choicesTechnographic studyArticle