<p>Writing for research publication is one of the primary means of disseminating knowledge in contemporary academia. It is through this particular form of knowledge dissemination that a rich body of scientific knowledge about a given phenomenon is accumulated. The primary goal of this dissertation is to explore the linguistic characteristics of this specific sub-register of academic writing. For this purpose, the study adopts a multi-perspective approach through which patterns of language use in research writing are investigated at three different linguistic levels: lexis, multi-word expressions, and general lexico-grammatical items. In doing so, careful consideration are given to disciplinarity, intra-textual variation, and L1-LX expert writing as key parameters of variation in writing for research publication. A secondary goal of the dissertation is to explore and highlight the benefits of methodological triangulation in corpus linguistic research. To this end, linguistic patterns in this study are identified, triangulated and verified through various inductive corpus-based analytical techniques to offer multiple, complementary perspectives on the discourse of research writing across disciplines. The data analyses in this dissertation are based on a representative corpus of empirical research articles (c. 4.5 million words) from a wide range of disciplines: biology, chemistry, dentistry, physics, mechanical engineering, applied linguistics, business, management, politics, and sociology. The analyses rely on both quantitative and qualitative assessments to provide a better understanding of the identified patterns. The results of these analyses show that the language of research writing is characterized by highly specialized and conventionalized discourses that are far from being homogeneous. It is found that such characteristics have the potential to govern the delineation of authors’ linguistic choices at various levels of language use such as lexis, multi-word expressions, and more complex lexico-grammatical linguistic structures. It is also found that any characterization of research writing with no careful consideration given to such factors as disciplinary writing and intra-textual variation would be incomplete. The results of the analyses also reveal considerable differences between L1 and LX expert writing in fulfilling the communicative practices related to the evaluation and elaboration of research findings.</p>