Knowledge and strategies in diagnostic skill

A theoretical framework for diagnosis in technical environments is presented, consisting of three layers. At the first layer, the task structure, top-level goals of the diagnostic tasks are identified that have to be fulfilled during task execution. This task structure may also be viewed as a global strategy to carry out the diagnostic task. The second layer of knowledge consists of the relevant local strategies by means of which values are obtained for goals in the task structure. The third layer consists of underlying domain knowledge. This theoretical framework is used to interpret the results as presented in the literature on diagnosis in technical environments. Finally, based on this framework, recommendations are made with respect to the training of diagnostic skill.