Lexical bundles across IMRD-structured Medicine research article sections: A within-register perspective

Employing a corpus of 1533 research articles in Medicine with a typical macrostructure pattern IMRD, this study investigates the cross-sectional distribution of four-word lexical bundles. The results show significant differences across the four IMRD sections in terms of the frequency of lexical bundle functions: both text- and participant-oriented bundles show a significant decreasing frequency distribution of D > I > R > M, while the pattern for research-oriented bundles is M > R > I > D. We find each section has one predominant lexical bundle: transition signals with I, procedure bundles with M, statistical reference bundles with R, and engagement bundles in D. We find within-register similarities in the bundle-functional profiles of I and D, R and D, M and R, and I and M. We explain these associations in light of the rhetorical functions of the IMRD sections and the embedded disciplinary culture of Medicine research. We draw on these within-register variations and similarities in formulating relevant pedagogical implications.