Rhetorical structure of the introductions of applied linguistics PhD theses

This paper examines the rhetorical structure of 20 introductions of applied linguistics PhD theses (AL introductions) produced in Australia, Canada, the UK, and the US. The results are compared with previous studies examining thesis introductions produced in other disciplines (OD introductions). The analysis shows that the AL introductions have a greater tendency to include research questions, descriptions of research subjects or material, and reviews of previous literature, while they have a lesser tendency to indicate problems or needs. Unlike the writers of the OD introductions, who were reported not to refer to their studies until in the closing paragraphs, the majority of the writers of the AL introductions do so from the opening paragraphs and at several places. These writers introduce their studies in general terms in the opening paragraphs as the introductory part and then describe or justify specific aspects of the studies in the body part, often followed by previews of the subsequent chapters as the ending part. The AL introductions following this pattern are found to be much longer than the AL introductions following the pattern of the OD introductions.