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Matching introductions and conclusions

The main aim in structuring your review of the literature is to lead your reader to the point where he/she can see no other option than the need to conduct precisely the form of research you are proposing. The introduction and conclusion to your review of the literature, as well as indicating how your research is going to bring to a satisfactory resolution unresolved questions in others' work, can also accomplish additional tasks. You can, for example, identify the key terms and concepts; you can outline the structure of the review itself - by preview in the introduction, or review in the conclusion - and you can then foreshadow the direction of the next section/chapter (see also Giving Reader Directions).

Consider the key terms in the following introduction to the literature review in a Masters Project in Linguistics and see how the student returns to them in her conclusion.

Example 1 topic: "Using computer technology to focus on form in corrective feedback: A case study".


2.1 The value of corrective feedback


Linguists and educationalists have for many years had conflicting views about the value of correcting linguistic errors[1] in the speech and writing of second language learners. With regard to the practice of correcting written errors, one extreme view is that corrections do not have a significant effect on student errors and teachers should, therefore, adopt less time-consuming efforts to direct students' attention to surface error (Robb, Ross and Shortreed 1986:91). The more moderate view does not dismiss the value of correction as a useful teaching technique, but rather, it emphasises the importance of consistency and systematicity if the positive effects of correction[2] are to be realised (Cohen and Robbins 1976:60; Rivers 1981:306; Lalande 1982:140).

In second language teaching/learning, the purpose in providing feedback such as 'correction', i.e., 'corrective feedback' (Schachter 1991:89), is to supply learners with 'negative evidence'[3] which attempts to draw their attention to the linguistic errors made (Ellis 1994:584), or to "what is ungrammatical in their sentences" (p. 434). According to Gass (1991:140), focusing attention on form through corrective feedback is similar to grammar instruction in the way that it alerts "learners to the mismatch between their learner language form and the target language". Indeed, a number of studies investigating the effect of corrective feedback in speech (Tomasello and Herron, 1989:394; Lightbown and Spada 1990:443; Carroll and Swain, 1993:372), and in writing (Lalande 1982:145) support the view that learners can improve their conscious knowledge of the target language[4] through a focus on form in the corrective feedback[5].


The above discussion has highlighted the benefits of using a concordancer as a research tool for investigating and focusing on regular patterns of language use. It reviews a range of previous applications that have used concordance data as stimuli for investigating students' linguistic errors. The technique proposed in this study extends on these previous applications by providing students with two types of stimulus for focusing on linguistic form: 1) the negative evidence of extensive corrective feedback, and 2) the positive evidence of concordance data which the students generate independently from a corpus of their own reformulated texts. The next section elaborates further on the proposed technique and provides a detailed account of the method used to trial it.

Note the key terms in the Paragraphs 2 and 3 of the following introduction to the literature review in a Chemical Engineering PhD. See how the student returns to them in his conclusion.

Example 2 topic: "Design of high-rate trickling filters"




The technical literature of trickling filters is very extensive. This is evidenced by the literature search and critical analysis published by Dow (1971), which cited over 5,600 references in the literature published up to 1968. An exhaustive review of the literature is thus beyond the scope of this work.

The aim of this chapter is to provide, through selective reference to some of the literature, a clearer understanding of the different microbiological, chemical and physical processes that occur within trickling filters. Experimental observations of various trickling filter phenomena are reviewed, and there is discussion of the sometimes conflicting conclusions about the mechanisms of trickling filtration that have been drawn from the empirical evidence.

The chapter is divided into two parts. The subject of the first is the biological film which is the site of the biological oxidation of organic matter from the wastewater, and is thus the heart of the process of trickling filtration. The formation of the biofilm is outlined, and the different processes which occur within it are discussed. The remainder of the chapter is devoted to a consideration of the operating variables which determine trickling filter performance.


Concluding Remarks

The review of literature in this Chapter has concentrated largely on empirical observations of trickling filters. At the micro level, the effects of oxygen and substrate limitations on the reactions occurring within the biofilm have been assessed. At the macro level, trickling filter performance has been considered in terms of state variables such as hydraulic rate and depth of packing. Certain important concepts, such as liquid residence time, have been introduced and used to explain, qualitatively, certain aspects of filter behaviour.

To quantify filter behaviour, it is necessary to develop a theory for the process; the theory may be a complex mechanistic model, or a simple empirical correlation. All trickling filter theories are based to some extent on empirical observation, if only for certain basic assumptions. Thus this Chapter provides a basis for the next in which the development of trickling filter theories is outlined, and various design equations are critically analyzed.

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