If you have decided or were assigned to write a literature review, remember that your primary goal is to encapsulate the main ideas of given topic or question. A literature review is not an exhaustive list of every possible study, but a synthesis and analysis of the current big ideas and future directions of a field. So how do you get started?
A literature review involves tedious work and lots of reading, so you should pick a topic that you are excited about as much as possible. Sometimes your advisor may assign a topic, which can limit your options, but in either case, it can be useful to partner with a mentor who can help you to narrow your topic to a very specific one or suggest some articles to get you started.
2. Find articles!
Once you have identified keywords, you can search databases (Web of Science, PubMed, Scifinder Scholar, Google scholar) to find journal articles (For information on finding articles check out this Scientista article). For some of these databases, you may be required to login through your university. Exclude literature that does not address your research questions or articles that you suspect might be of low quality- red flags include: literature that does not fully explain its methods or results, that has poor experimental design or fails to cite relevant literature. There may also be other literature reviews published on your topic, which can provide a background or starting point for important publications on your chosen topic. It’s important to keep a list of keywords and use a reference software (I like Mendeley because it’s free and integrates well with Microsoft Word) to organize your articles and notes. Also, read the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, which gives important guidelines that researchers in the biomedical sciences should follow and that certain journals also require.
3. Start reading furiously and take notes!
Which topics keep coming up, over and over again? Are some results conflicting? What are the most common conclusions of the articles? Is there unknown information not addressed in the results or conclusions? Organize your notes by topic and theme and share them with your mentor. They will be able to give you feedback on your progress so far. Your mentor may send you back to the drawing board or suggest other articles, and you may need to refine or broaden your scope based on the literature. Do not get discouraged, and remember that this is part of the research process!
4. Get to writing!
Once you have narrowed your notes to the major conclusions or findings, you can get started outlining your review. The content of your review will vary greatly based on your topic, but it should include: 1) a general introduction to the topic and the goal of the review, 2) a current synthesis of the available data and 3) areas of research that still need to be investigated. To get you started, download the outline by Dr. Amanda Riojas [Outline: Literature Review].
Julie F. Charbonnier is a 4th year PhD candidate in Integrative Life Sciences at Virginia Commonwealth University. Her research focuses on amphibian and population ecology. She is also interested in scientific writing and public policy. You can follow Julie on Twitter @modernecologist