Epistemic modality in social science research articles written by Ghanaian authors:a corpus-based study of disciplinary and native vs. non-native variations

Using a corpus-based methodology, this thesis reports a study into how non-native Ghanaian academic authors of English in the disciplines of Sociology, Economics and Law deploy epistemic modality devices as rhetorical features of argumentation in their research articles (RAs) published in journals based in Ghana. The study focuses on understanding the ways in which the use of these rhetorical features by Ghanaian authors compare with their use in international RAs written by native academic authors of English. Based on the aims of the study, two sets of corpora of RAs for the Ghanaian and international authors were created and analysed to compare the use of epistemic modality features between the two groups of authors in terms of: depth of use, diversity of use, linguistic types of epistemic markers, phraseological patterns of notable epistemic markers and degrees of epistemic strength. The quantitative aspects of the comparisons relied mainly on frequency counts of epistemic markers which were supported by Log-likelihood tests to determine significant differences of epistemic use across disciplines and between the two groups of authors. The qualitative aspects (e.g., phraseological pattern analysis) focused mainly on a close inspection of concordance lines for comparisons. The findings of the study revealed that while Ghanaian writers seem to be generally aware of the most important epistemic devices used for academic writing, as they used as wide a range of epistemic devices as their international counterparts, they tended to use these devices significantly less in their RAs. A few cases of overuse and misuse of epistemic modality by Ghanaian writers were also observed. It was found also that many of the disciplinary variation patterns of epistemic use observed in the international RAs did not match with the patterns revealed in the RAs written by the Ghanaian authors. A further important finding was that whereas the international writers generally preferred medium and weak level epistemic markers over strong ones, the Ghanaian writers favoured the use of medium and strong level epistemic markers over weak ones. It also became apparent that the significant underuse of epistemic rhetorical features by the Ghanaian writers could be attributed to the way rhetorical features are represented in academic writing course materials in Ghanaian universities. The findings reported in this thesis suggest that there is the need for Ghanaian academic authors to make language adjustments to their academic writing if their writing practices are to fully adhere to international disciplinary norms and conventions