Research writing is vital in higher education, particularly in research-orientated institutions. It has been widely discussed and instructional implications have been raised. However, research writing in the theoretical framework of Systemic Functional Linguistics (SFL) is still a new discovery in the academic research discourse. There are different views on research writing and it depends on different factors such as subject areas, purposes, methodologies and perspectives. However, there are some common features of research writing which can be seen in the formality and complexity of written language.

This presentation reports an exploratory study based on the analysis of four research abstracts to examine the grammatical complexity of research writing from the SFL perspective. The analysis focused on three grammatical features namely, lexical density, nominalisation and nominal groups. The findings show that the abstracts of research articles are of high density in terms of lexical words and information. It also reveals that the abstracts show high occurrence of nominalisation and the complexity of nominal groups.

It is concluded that nominalisation and nominal groups are the typical features of lexical density in research writing as more lexical items are packed in nominal groups and there is high frequency of embedded clauses functioned as qualifiers in the nominal groups. The results suggest that lexical density, nominalisation and nominal groups can provide useful insights into research writing and can have pedagogical implications for teaching research writing.