Congratulations! You’ve been accepted into a graduate program and you’re thrilled with the prospect of doing groundbreaking research work. But hang on a minute; before diving straight into a new project, it is worth taking some time to perform a literature review. A review of existing literature can establish the importance of your work, and lay the foundation for future research direction, all while ensuring that you’re not repeating someone else’s experiment!
What’s the Point?
A literature review is essentially a piece to highlight the importance of your research. It is a combination of an up-to-date summary of the current state of research, a means to highlight problems and limitations with existing literature and a way to establish the significance of your work.
Many graduate programs require you to submit a literature review before you begin research. If this isn’t the case, it can be beneficial for you to carry out your own review of the literature. This is to ensure whatever work you plan on carrying out has not been done before, and that your research direction will make a significant impact in your field.
However, a literature review can also be done before submitting a manuscript to a publisher, or before writing a thesis/dissertation. This will entail a more targeted review, to establish the significance of your already-performed research and to show that you have a strong grasp of the current research landscape.
5 Steps to Writing a Literature Review
Step One: Plan
As with any project, the planning phase is arguably the most important. The first thing to do is to lay the foundation in the form of a central argument or ‘thesis’ statement. Although a literature review is a summary of existing research, the information within is focused on your thesis. The thesis is also what your research will address directly, either supporting it or opposing it.
Before beginning a literature review, it is important to define two aspects of it: the scope and type of review. The scope will help narrow the list of papers and journals to choose from. Which academic fields will it address? Some reviews will encompass multiple disciplines, while others will be more focused.
The type of review largely depends on your thesis and your field of research. Will there be an emphasis on theory or experiment? Will the studies be qualitative or quantitative? This will also make it easier to find relevant sources and information for the next step.
For example, your research may be to compute new ways in which snowflakes form. A thesis, in this case, could be that ‘all snowflakes have six-sided symmetry’. The scope of such a review could include physics, computational chemistry and atmospheric chemistry. If the review was more focused, the scope might be limited to the mathematics of nucleation pathways.
Step Two: Read
Once you’ve identified your thesis, the next step is to gather and read as much relevant literature as possible. It can be worth writing down some notes about each paper, such as the author’s main thesis or how the study relates to your own project, to make it easier to come back to if needed.
There is just so much literature available today, even in the most niche of research fields. It is virtually impossible to read every journal paper that has been published in your field, therefore databases with advanced search functions such as Web of Science, Scopus, or even other review papers can be useful as secondary sources.
Given the wealth of information available, it can be tempting to include as many sources as possible to address every theory or method in your literature review. There is no hard limit on the number of references or even the length of your review but remember that your time is valuable. A handful of relevant and up-to-date sources are often enough.
Step Three: Critique
The next step after collecting your sources is to critically analyze them. Remember that a literature review is your own perspective on the state of research, therefore collating existing information isn’t enough. Your critique should address both individual studies as well as the overall state of the field, linking it back to the importance of the studies you plan on carrying out.
Make comparisons between individual studies, stating their strengths and weaknesses. Do not be afraid to critique methods or results you believe are flawed, explaining why and how they can possibly be improved on. This is especially important if your research aims to improve on an existing technique or fill knowledge gaps in a certain theory.
Provide your perspective on the current state of research, such as key theories and ideas. A literature review is also an opportunity to highlight trends and paradigm shifts in research. For example, a literature review on gene therapy techniques might attribute recent successes to the development of CRISPR-Cas9 technology, showing how it has helped to advance the field.
Step Four: Write
Now that we have all the pieces for a literature review, the actual task of putting it all into words becomes simple.
Start off your introduction by providing your thesis, citing key facts and figures that support it. For example, ‘research into ___ over the past decade has uncovered several interesting ideas, theory A and theory B…’. Move on to highlight the importance of further work and how it will benefit the field.
The bulk of the literature review should contain your summaries of existing work, the state of the field, as well as your opinions and perspectives. Organize the information in a way that makes sense to a new reader; this can either be in chronological order, by topic or by a specific theory. There isn’t a strict rule on the structure as long as your writing follows a clear logical flow. Also, your friends and family make for great (if admittedly reluctant) proofreaders!
Finally, the conclusion of your review is a summary of the literature as well as an overview of your perspective. It should also explicitly emphasize the knowledge gaps you have found, providing avenues for further research. Your own research should aim to fill these gaps, although it is unlikely that it can address them all.
Citations are also important throughout – after all, your research wouldn’t be possible if not for the generations of academics who have laid the foundations for it. Any fact, figure or theory used that is not your own must be cited. The preferred citation style varies from field to field.
Remember that while the information you reference comes from somebody else’s study, a literature review is your own work! As mentioned in Step 3, it is appropriate and even encouraged that you include your own opinions or criticisms of existing sources with respect to your thesis.
Step Five: Review
After countless hours, you’ve finally completed a draft of your literature review – now it’s time to review your review. Editing begins with reading the entire piece through to see if the review flows well from one point to the next. Oftentimes simply moving paragraphs around can improve readability.
When we use information from so many journal papers, it becomes difficult to weave them together so that they fit our purpose. Ensure that all sources work to support your main thesis, otherwise, they serve no purpose and should be removed.
Always go back to your thesis, asking whether your literature review backs up your research direction. Conversely, ask yourself whether your planned research serves to improve the field. Based on what you’ve uncovered in the literature review, do you have the capacity to make a significant contribution?
The literature review is a powerful tool to assess the landscape of your research field. Through this process, you might realize that studies identical to your own have been done, or that your focus might not impact the field in a significant manner. A literature review can help to guide your research direction and improve your effectiveness as a scientist.
Science Literature Review Samples
You can find links to several example reviews below: