Distinguishing textual features characterizing structural variation in research articles across three engineering sub-discipline corpora

• Three sizable corpora of three engineering sub-disciplines systematically compiled.
• Comparison of textual structure at the move and step levels in four sections conducted.
• Significant statistical variations as distinguishing features across the sub-disciplines.
• The same moves for each section of the sub-disciplines share the same function.
• Step variations reflect how the knowledge in each sub-discipline is presented.

Genre analysis has provided insights into the textual organization of different genres. In the research article (RA) genre, previous studies demonstrate that disciplinary variation is discernible. To raise the investigation to the level of sub-disciplines, this study addresses two research questions: (1) What is the textual organization of individual RA sections in corpora from three engineering sub-disciplines? and (2) What are the significant statistical variations in textual organization that distinguish one engineering sub-discipline from another? Initially, three corpora were compiled, consisting of 180 full length high quality RAs representing three sub-disciplines of engineering (civil, software, and biomedical). Then, the corpora were analyzed using genre analysis to identify the textual organization prevalent in individual RA sections of each engineering sub-discipline. Subsequently, units of textual analysis called ‘move’ and ‘step’ were quantified and statistically analyzed to capture significant statistical variations in each section. The analysis reveals the influence of the sub-disciplines on the textual organization variations across the corpora, highlighting the unique characteristics and perspectives of each sub-discipline. The findings contribute to enhanced quality professional communication by creating and raising awareness and sensitivity among prospective engineering students and practitioners when they are involved in the task of reading and/or writing RAs.