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Variation and Diachronic Change in Epistemic Stance: Testing Promotional Trends in NSF Grant Proposal Abstracts.
Although epistemic stance in academic discourse has been extensively researched
in linguistics, relatively little is known about diachronic change and variation in its expression
across disciplines, and still less about the grant proposal abstract, a genre produced under strong
promotional pressure. The present paper addresses this gap by testing whether the widely report-
ed trend towards research “hype” is reflected in the epistemic stance of grant proposal abstracts
and, if so, whether it is uniform across disciplines. We examined three groups of epistemic stance
expressions (hedges, boosters, and modal auxiliaries) in a 99.4-million-word corpus of openly
available abstracts of successful NSF grant proposals representing seven disciplinary groups (bi-
ological sciences, computer and information science, engineering, geosciences, mathematical and
physical sciences, social, behavioral and economic sciences, and education) and spanning the pe-
riod 1987–2024. Using Kendall’s tau and linear regression, complemented by autocorrelation di-
agnostics, we established whether there is a consistent upward or downward trend in the incidence
of these features in each discipline over time and estimated the size of the differences. The results
complicate the picture drawn by existing discipline-specific studies of epistemic stance. Contrary
to the upward trend observed in medical research abstracts, the frequency of boosters decreases
consistently across four disciplines and in the corpus overall; the frequency of hedges follows a
comparable downward trajectory, and modal auxiliaries decline overall, a trend accounted for
largely by the high-frequency future marker will, though one that falls short of our consistency
criterion, while individual modals move in opposite directions. These findings suggest that trends
in the expression of epistemic stance are highly dependent on discipline and genre, and that the
assumption that the language of research is becoming uniformly less cautious and more promo-
tional merits comprehensive, cross-disciplinary empirical examination. The study contributes to
ESP research by demonstrating that the promotionalisation of academic writing does not operate
uniformly across professional genres and disciplines.