Working on an applying corpus consisting of lectures and scientific articles belonging to hard sciences, social sciences and humanities, in the present article my aim is to identify and describe within the frame of Argumentative Semantics the characteristics of the evidentiality adverbial 'evidentemente' in written academic discourse. In the first place, after a quantitative and qualitative analyisis of the corpus, we can state that this marker proves to occur more frequently in factual sciences, which may lead to an explanatory hypothesis: indeed the occurrence of 'evidentemente' is related to the discoursive configuration of every single discipline, that is to say, to the effects of scientificity caused by the construction of the object of study and by the presence of a locutor as a mediator of the described phenomena. In the second place, and with the intention of overcoming certain contradictions which arise from the analysis of bibliography -in fact, 'evidentemente' is considered a booster by certain academics, while others consider it an evidential of inference, which mollifies the locutor's degree of certainty- I suggest a new analysis based on examples provided by a corpus of samples taken from factual sciences.