Although there might be a chapter called the “Literature Review”, (in most cases) literature is reviewed in a number of possible places, including the introductory and methodology chapters or sections (see example 1).

Across all these possible locations, literature reviews must:

  • convince the reader as to the significance, importance or interestingness of the research questions being considered.
  • convince the reader that the thesis will make an original contribution to the area being investigated (this requires the review of relevant background material so as to identify gaps, weaknesses, problems or controversies that need to be addressed).
  • critically review the different methodological approaches that researchers use in your field to investigate questions like yours so as to justify your choice of methodology, data to be collected, instruments to be used, and so on.

They may also:

  • critically review the theory which will be needed for the analysis of your results (Okay, you’ve got your data, but what do they mean?).
  • use the results of previous research to identify a promising direction for future research (see example 3).

As such, literature reviews:

  • need to be framed as arguments, not merely summaries.
  • demonstrate your professional competence in the field (you know what’s “hot”, what's controversial, what's a landmark or seminal paper, what's “state-of-the-art”, and what's advantageous or disadvantageous about the different methods for achieving your desired research objectives. See for example: http://www.cebm.net/index.aspx?o=1039).

How extensive reviews must be varies according to level. That is, more is expected of a PhD thesis than an honours or MPhil thesis.

While all literature reviews share the common feature of providing a justification for the research undertaken, there is considerable variation in the details of how this is done. Consequently, it is important to be able to analyse literature reviews in your discipline for yourself so you can work out precisely what’s required and what might be a good structure (but you shouldn’t just mindlessly copy what others have done, you need to think about what your thesis needs in order to convince the reader). Example 4 shows how a literature review can be analysed for its structure and the type and purpose of its elements of content (see also example 1).

A question you might have here is, “How does the Literature Review differ to what was done in the Introduction?

In many scientific journal articles, this question doesn’t arise as the Introduction incorporates the literature review, but in many other disciplines, journal articles have separate Introductions and Literature Review sections. To get an understanding of how the two sections complement rather than repeat each other, it is probably best to have a look at a few (well written) examples from your discipline and ask yourself, “what sorts of things are being addressed in each section?” (see example 4) for an example of what this looks like.)

In general terms though, you will probably find that the Introduction to a thesis identifies:

  • the general importance or significance of the broad area of study (e.g. if you were doing research into malaria vaccines, you would probably start by identifying how many people are affected by malaria each year, the personal and economic cost of this, and in broad terms, the limitations of current treatment approaches.)
  • your aims/objectives. (More specific aims or hypotheses will come out of your literature review, or if your thesis is organised such that each body chapter is effectively an article for publication, then more specific aims or hypotheses will come out of the Introduction/Literature review for each chapter.)
  • the structure of your thesis. (But note, if this is basically just a statement of your table of contents in paragraph form, then there is rarely any point doing this. See Dr Leslie Sage’s comments on this at the end of her article. (see also example 1)

In contrast, the Literature Review provides a more detailed analysis of existing literature and shows how this literature informs your research (see: “Identifying promising lines of research” below), and how deficiencies in this literature provide a motivation for your research.