Much advice about literature review writing warns against the ‘laundry list’ (e.g. “Brown (2008) studied A and found Y. Roberts (2012) investigated B and found X and Y. Peterson (2007, 2013) conducted a long-term investigation into C and found X, Y and Z.”).
For your argument about the literature to come through clearly, the review must have a structure. It must make connections between the works you have read, and between them and your own study.
This diagram represents the elements that feed into the structure of your literature review.
There is no single “correct” structure, since every review is shaped by the nature of the field being reviewed and the particular needs of the study the review is supporting.
Some common organising patterns are:
- themes or concepts
- approaches to a question
- historical development.
They may be used in combination. Usually there is a move from general overview to specific studies within the sections of a literature review, however they are determined. The more important works are to your own research, the more detailed your analysis will be.
This move in focus, from the wide-angle view to the close-up, can also work at paragraph level. The following example moves from distant to close (in terms of relevance and applicability) as well as chronologically. It moves from 1) the broader historical context to 2) the implementation which demonstrates superior performance, and then to 3) the implementation which provides the model to be tested for the study.
Click on the text to see the three moves highlighted.The general text for the area of information retrieval is more than 10 years old (Salton & McGill, 1983). Yet, the methods of information retrieval mentioned are still relevant today. Van Rijsbergen (1979) describes probabilistic retrieval, which is the model that the Bayesian network implementation of information retrieval system is based on. Of the implementations of such systems, Turtle's (1990) implementation appears to be the most well-known and demonstrates superior performance compared to Boolean and vector space methods. Ghazfan et al. (1994) have produced a different implementation which has not been tested in an actual information retrieval system. It is the purpose of this investigation to obtain performance results in an actual information retrieval system..
Introductions and conclusions
The main aim in structuring your review of the literature is to lead your reader to the point where they can see no other option than the need to conduct precisely the form of research you are proposing. The introduction and conclusion to a literature review chapter will indicate how your research is going to bring a satisfactory resolution to unresolved questions in others' work. Not all introductions and conclusions will include all of the points listed below.
The introduction may:
- contextualise the review, perhaps by relating it to the research question(s)
- identify the key terms and concepts
- summarise overall trends
- justify the selection of literature
- outline the structure of the review itself.
This short introduction to the literature review from a thesis on the design of high-rate trickling filters performs some of these functions. Click on each paragraph to identify its function.
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 and structure of the biofilm (or slime layer) 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.
The conclusion may:
- recapitulate significance of key studies
- evaluate the current state of the area
- establish the relation of your study to gap(s) in research literature (or show how your study builds on existing research)
- foreshadow the direction of the next section/chapter.
Look at the final paragraphs of the same review, then answer the questions below.
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 analysed.
Which elements of a conclusion do they include?
TipLook at theses in your discipline to see what they include in the introductions and conclusions of their literature reviews. The Theses Library Guide provides information on locating and accessing theses produced by Monash University as well as other institutions.