Generic Features Of Literature Reviews In Research Articles In Science And Engineering

Researchers have been increasingly more interested in academic genres since the 1990 s. The seminal work of Swales’ genre analysis(1990) has led to wide spread interests in demystifying the features of research articles(RAs). There are studies focusing on the analysis of the overall features of RAs or separate sections of RAs. Literature Reviews(LRs) are essential to the construction of RAs. They help map the research field and position the present research within the context of the research community. In RAs, LRs can appear in the form of standalone LR chapters(SLRs) and embedded literature reviews(ELRs) in RA introductions. This research is carried out with the assumption that LRs are an independent academic genre, and SLRs and ELRs are both subgenres of LRs.This paper attempts to explore the generic features and other rhetorical features of LRs by comparing SLRs and ELRs, thus contributing to the ongoing research on academic discourse and hopefully providing pedagogical implications for EAP(English for Academic Purposes).Based on Genre Analysis theory and Swales’(1990) Create a Research Space model(CARS model), this thesis mainly explores the similarities and differences in both macro rhetorical features and micro linguistic features between SLRs and ELRs with an integrated approach that combines quantitative and qualitative analysis. To conduct the research, two small corpora, with one consisting of 40 SLR texts and the other consisting of 40 ELR texts, are compiled. These texts are selected from ten international journals with high impact factor such as Applied Energy, Global Environmental Change and Transportation Research, and they cover a wide range of topics in science and engineering. There are altogether 80 texts with a total of 87,986 words for analysis.The research is carried out in three main steps. First, the constituent elements in each sample are identified with the help of linguistic signals and the frequency of each element is calculated. Second, the rhetorical moves of the samples are identified according to various rhetorical functions of the constituent elements. Then, the samples are analyzed from a micro linguistic level perspective to identify the lexical grammatical features of the two subgenres.The research has yielded significant results summarized as follows.At the macro rhetorical level, SLRs and ELRs share the same communicative purposes to a large extent—to establish the context of the intended research, to show that the researcher has read extensively in an academic area and to prevent duplication of research effort, which accords with the communicative purposes of LRs. More importantly, SLRs and ELRs share the same strategies in organizing the reviewed literature: They are “Theme-Elaboration”, “Classification-Elaboration” and “ProblemSolution”. These similarities attest to the conceptual assumption of this study that SLRs and ELRs belong to the same genre of LRs. Meanwhile, the overall discourse structure in which the SLRs and ELRs are placed is different. The SLRs have an introduction of their own which provide some background information about the related issues, revealing a distinctive rhetorical function of SLRs—to help the reader understand the research problem; while ELRs are placed in the CARS model for the purpose of “establishing a territory”, indicating a distinctive rhetorical function of ELRs—to account for the reasonability of the intended research. The distinctive local contexts determine the peculiarity of both SLRs and ELRs and shows that they are two subgenres of LRs.At the micro linguistic level, SLRs and ELRs also share similar lexical grammatical features. Firstly, the opening sentences in both SLRs and ELRs often express popularity of the topic, the focus of the research to be reviewed or the scarcity of the literature. Therefore, quantitative words such as “many”, “most” and “a number of” are frequently used. Secondly, integral citations and simple past tense are often used when specific experimental research is reviewed. But when giving an overview of the topic, non-integral citations are often used. Besides, passive voice is often used to describe the experimental procedures. Thirdly, frequently used reporting verbs in the corpora include “develop”, “find”, “investigate”, “study”, “show”, “examine”, “conduct” etc. Another major finding is the similarity in the use of negative quantifiers such as “little” and “very few”, and lexical negation such as “scarce” and “less”. These words are often used in both subgenres either to express the scarcity of the literature or to indicate a gap in the existing knowledge.To sum up, findings of the present study show that there are both similarities and differences between SLRs and ELRs, which attests to the assumption that they are subgenres of the same genre. This conceptual formulation in turn helps explain the communicative purposes, the information organization patterns and the linguistic features SLRs and ELRs share. On the other hand, the two subgenres are placed in different context, implying that each of them has to fulfill rhetorical functions that the other does not.The findings may have important pedagogical implications. The rhetorical move structure of the two sub-genres and the linguistic features will provide new ideas for what to teach in English for Academic Purposes courses.