Literature reviews

New discoveries don't materialise out of nowhere; they build upon the findings of previous experiments and investigations. A literature review shows how the investigation you are conducting fits with what has gone before and puts it into context.

If you are doing a thesis, dissertation, or a long report it is likely that you will need to include a literature review. If you are doing a lab write-up or a shorter report, some background reading may be required to give context to your work, but this is usually included as an analysis in the introduction and discussion sections.

A literature review is a select analysis of existing research which is relevant to your topic, showing how it relates to your investigation. It explains and justifies how your investigation may help answer some of the questions or gaps in this area of research.

A literature review is not a straightforward summary of everything you have read on the topic and it is not a chronological description of what was discovered in your field.

A longer literature review may have headings to help group the relevant research into themes or topics. This gives a focus to your analysis, as you can group similar studies together and compare and contrast their approaches, any weaknesses or strengths in their methods, and their findings.

One common way to approach a literature review is to start out broad and then become more specific. Think of it as an inverted triangle:

• First briefly explain the broad issues related to your investigation; you don't need to write much about this, just demonstrate that you are aware of the breadth of your subject.
• Then narrow your focus to deal with the studies that overlap with your research.
• Finally, hone in on any research which is directly related to your specific investigation. Proportionally you spend most time discussing those studies which have most direct relevance to your research.

Start by identifying what you will need to know to inform your research:

• What research has already been done on this topic?
• What are the sub-areas of the topic you need to explore?
• What other research (perhaps not directly on the topic) might be relevant to your investigation?
• How do these sub-topics and other research overlap with your investigation?

Note down all your initial thoughts on the topic. You can use a spidergram or list to help you identify the areas you want to investigate further. It is important to do this before you start reading so that you don't waste time on unfocussed and irrelevant reading.

It's easy to think that the best way to search for texts is to use the Internet - to 'Google it'. There are useful online tools that you may use, like Google Scholar. However, for most literature reviews you will need to focus on academically authoritative texts like academic books, journals, research reports, government publications. Searching Google will give you thousands of hits, few of them authoritative, and you will waste time sorting through them.

A better idea is to use databases. These are available through the Library in paper and electronic (usually online) forms.

Use journal articles: They normally have the most up-to-date research and you will be expected to refer to them in your literature review. The Library has a guide on finding journal articles. 

The Library also has an Academic Liaison Librarian for each subject and guides to finding information in your subject. 

You may find review articles that survey developments in your field. These are very useful for identifying relevant sources - but do go back to the original texts and develop your own critical analysis if possible.

Another good way to find sources is to look at the reference lists in articles or books already identified as relevant to your topic. You will be expected to prioritise recent research, but it's also important to acknowledge the standard texts in your field. An easy way to identify these is to check reference lists to see which texts are frequently cited.