The senior thesis is a relevant discourse genre to prove academic knowledge and to obtain a university degree. The descriptions of this kind of genre have been focusing on the lexical-grammatical and discursive rhetoric level; as well as in the process of construction and defense of the thesis. The semantic level, however, has been scarcely studied. This paper describes the characteristics of the authorial attribution of knowledge given by the semantic representation of utterances of the introduction and conclusion section. The corpus comprises 364 senior theses of four disciplines. First, we extracted utterances with explicit authorial attribution. Secondly, we constructed the semantic representation of statements according to the Role and Reference Grammar (RRG). According to the results, we can highlight the use of the first person plural as the first argument of verbs of activity in structures do' (x, [pred' (x, y)]), mainly in the conclusion section. The thematic role perfomer presents a high frequency in all four disciplines. Speaker and judger are also very frequent in the x argument. Consequently, the most common macro-role is Actor. Finally, it is interesting to note the potential of using RRG in academic discourse analysis.