The major factors influencing and determining the effect of an interpretation are Credibility, Representability, Elegance, Diversity, Immediateness and Technicality (CREDIT). The article presents a 'CREDIT' model in order to evaluate the general impression involved in an interpretation. The elements of this model are defined, quantified and justified by means of a number of examples. The article presents seven methods to collect the necessary data. Finally a number of of suggestions are formulated to further improve the model.