Research articles and research theses constitute two key genres used by scientific communities for the dissemination and ratification of knowledge. Both genres are produced at advanced stages of individuals' enculturation in disciplinary communities present original research aim to persuade the academic community to accept new knowledge claims, and are the result of social negotiations between authors and disciplinary gatekeepers. However, despite their similarities, these two academic genres differ as regards the status of their authors in academic discourse communities and the power asymmetries between themselves and disciplinary gatekeepers. Awareness of these differences in relations of power and of the social forces behind the formation of genres, which are constituents of advanced academic literacy, defines the rhetorical strategies used by the authors of these two genres. This is revealed by a comparison of 17 research articles and nine samples of research theses from the fields of electronic and chemical engineering. The analysis of the texts focuses on the density and function of hedges and, in particular, discourse-based strategic hedges and of their personal or impersonal expression. The analysis indicates that students hedge more than expert authors and virtually wholly refrain from taking personal responsibility for their claims. Expert authors, on the other hand, hedge less than the students and often use personally attributed hedges. The comparison additionally indicates differences in the frequency of certain types of strategic hedges between RA authors and students. (Contains 10 tables.)