How to write a systematic literature review
the already printed articles; you want to know what is going on in your
field of study and raise your awareness. Then you either come up with
new interpretations; combines new and old discoveries to form you own
literature review; or track a particular process in the literature.
Okay, first let’s start by some standard definitions:
What is (traditional) literature review?
In traditional literature review methods, the researcher simply reads the article which he thinks is relevant to his study and then writes a summary.
Then he/she goes to next article and writes its summary too. This is
the traditional method of carrying out a literature review which is time
consuming and, let’s be honest, out of date.
What is systematic literature review?
Here is one definition: ‘Systematic
review is a review of a clearly formulated question that uses
systematic methods to identify, select and critically appraise relevant
researches, and to collect and analyze data from the studies that are
included in the review.’  In a systematic review the researcher identifies and defines the things very well; appraises and interprets everything
he/she finds in the research resources; finds the relation of each
article with each research question; forms a chain along the field
he/she is interested in. In short, systematic review is well planned and follows pre-specified criteria. It uses clear protocols to find, evaluate and synthesize the results of relevant research.
A systematic review must have:
- Specific inclusion/ exclusion criteria:
it means you should set criteria based on which you can include or
exclude articles you will encounter during your writing process. There
may be hundreds of paper in your field of interest and for instance 60
years’ pile of body of knowledge. You cannot possibly cover every single
article in your field.
- Explicit search strategy:
what are you going to search for? How are you going to select your
articles? First, you have to search based on your keywords so that you
would find only relevant articles, this way you will narrow down your
search scope. Second, you should decide on a time-span, you cannot
simply go through all the studies and articles. By choosing an explicit
search strategy you will search systematically! (here you can find the tools which help you in finding suitable keywords, you can also take a look at this article)
- Systematic coding and analysis of included studies: now you want to select a number of articles which are not only relevant to your topic and keywords, but also have internal relevance,
what it means is that the papers you select should also be internally
related to each other. You can achieve this by using citation tracking
tools which we have introduced here.
This way you can create a link between your findings and create a chain
which can help you in finding certain shifts or processes in the
Okay, now here are the steps to follow when conducting a literature review:
Step 1: Formulating questions for review
The problems to be addressed should be specified in the form of
clear, unambiguous and structured questions before beginning the review.
A clear, specific and answerable question is essential to a successful review.
Step 2: Identifying relevant work
We actually talked about this step above, in “Systematic coding and
analysis of included studies”. You should act based on your criteria too
and record your reasons for inclusion and exclusion of certain
articles. You should use citation tracking tools to find articles which
are internally linked to each other. This way your job will become much
easier. Here is a video which can help you in this regard.
Step 3: Assessing the quality of studies (critical appraisal)
We must know how to appraise the resources we obtain. There are many
factors to consider such as author, publication time, publisher, journal
and content. You can begin by assessing the scientific level of the
author and check his H-index or number of citations he has receive. You
can look up the journal which has published that article and check its
impact factor to find out its rating by Thompson & Reuters. There is
also the matter of content analysis which you should do yourself. Here
are some factors which help you do the content analysis and assess the
quality of a certain paper:
- Appropriateness of study design to the research objective
- Risk of bias
- Statistical issues
- Quality of reporting
- Generalize ability
- You can watch this video on article assessment
- You can find a “Critical Appraisal Work Sheets” here which will help you in doing quality assessment.
So now you have selected a number of papers based on your criteria
and assessment results. This means that you will not be wasting your
time by reading irrelevant articles. So, the next thing you should do is
to read your selected articles and write a report for each one. You
should write at least 150 words that capture the heart and soul of each
article. You can again save research time by reading the “results and discussion” section and “conclusion” section of each paper.
Step 5: Synthesizing and analyzing
When selecting articles and while writing, try to group the
literature according to common themes. You do not want to just report
the findings or list references. You are doing this to find trends,
shifts, gaps, or conflicting results. Decide on a sequence; go from
general to specific or most important to less important findings; find
relationships and connect findings; summarize major contributions of the
literature; evaluate the findings; adopt critical thinking. Your review
should be a whole; it must enjoy coherency and logical sequence.
Finally some tips to remember when conducting a systematic literature review:
- Do not start without a plan
- Do not read everything you find – evaluate first.
- Read and write – at least 150 words for each article
- Be critical and analytical – do not accept everything at first
- Literature review is not a descriptive list of the information gathered
- Literature review is not a summary of one piece of literature after another
- Manage your references – use Zooter, EndNote, Vistorio, Mendeley, etc.
In writing this review resources form the websites of University of Edinburgh, RMIT University and University of Nottingham were used.
How to write a systematic literature review - TCFEX