Lexico-grammatical properties of abstracts and research articles. A corpus-based study of scientific discourse from multiple disciplines.

Research articles are acknowledged to be the most important form of scientific discourse. Abstracts are, apart from the title, the first meeting of readers with research articles. Independently of their traditional purpose to summarize research articles, abstracts have become crucial for readers in the decision process of reading the text further, especially nowadays due to the vast amount of scientific publications. The growing importance of abstracts in academia and the few existing research focused on these have motivated this present research, which explored the relationship between these two text types in a broader linguistic context and investigated the linguistic differences between abstracts and research articles based on the quantitative analysis of the distribution of selected features. This research is rooted in Systemic Functional Linguistics, a sophisticated linguistic model, making possible the analysis of the relations between language and different social contexts and allowing a detailed investigation of discourse variation based on the analysis of linguistic features. This theory suggests a corpus linguistic methodology and the interest in functional variation of language is inherent in it. For this study, a corpus of English abstracts and research articles of the disciplines of computer science, linguistics, biology, and mechanical engineering was compiled and processed according to current practices in corpus linguistics. The study applied a twofold methodology. First, a deductive empirical analysis was performed, by which selected features were quantitatively determined and statistically evaluated for significance and hypothesis testing. Then, an inductive empirical analysis was conducted that corroborated the results of the deductive analysis that ascertained the adequacy of the hypotheses and features chosen. The results indicated that abstracts and their research articles are significantly distinct from each other together with a clear domain specific variation. This research contributes further to the linguistic investigation of scientific discourse. Not only linguists interested in language variation profit from the results acquired here. Such a research can contribute to the area of English for Special Purposes, having pedagogical applications in teaching of contemporary academic and research English inasmuch as understanding a certain discipline and practices of its community involves understanding their literacy