Systematic literature reviews can be intimidating, but they can improve a thesis considerably! Learn more about systematic literature reviews and their benefits. And have a look at a simple step-by-step guide that breaks down the daunting task of conducting a systematic literature review into simple, actionable steps.
What is a systematic literature review?
Systematic literature reviews are a means to rigorously review existing literature on a specific topic. They collect and analyse existing literature in a systematic and replicable way.
Following the definition of a topic of interest and concrete research question, a systematic literature review starts by defining several keywords. Then, academic citation databases are used to retrieve all articles that include these keywords.
Furthermore, inclusion and exclusion criteria for sorting through the existing literature are set up. Think of a time frame, the type of publication (articles, books etc.), a geographic focus, and a disciplinary background. You name it.
Systematic literature reviews are crystal clear about the process of collecting and analysing literature, which makes them replicable.
While systematic literature reviews require a lot of work, they can convincingly draw conclusions on the state of the art of existing knowledge, uncover research gaps, and support the creation of new theoretical and conceptual frameworks.
The difference between a systematic and a regular literature review
Before starting to consider whether a systematic literature review is right for you, it is important to be aware of the main differences between systematic and regular literature reviews.
The main differences between a systematic and a regular literature review are the process of collecting and analysing literature, the accuracy of claims, the scope and replicability.
In a regular literature review, authors select articles or other publications ad hoc, to support the arguments of their work. Authors make claims about the state of the art of academic knowledge on a specific topic, but do not necessarily provide systematic evidence to support their claims.
Therefore, the level of accuracy differs in systematic and regular literature reviews.
Furthermore, authors doing regular literature reviews generally do not explain how they conducted their review, and how they selected relevant literature. Therefore, regular literature reviews are usually not replicable, whereas systematic ones are.
Additionally, the scope of a review differs immensely between systematic and regular literature reviews.
Systematic literature reviews tend to methodically analyse hundreds of articles, whereas regular literature reviews are much more limited in scope and highly selective in their choice of publications that are included.
The difference between a systematic literature review and a meta-analysis
Systematic literature reviews are often mixed up with meta-analyses, or the terms are used interchangeably.
However, a systematic literature review is not the same as a meta analysis!
A meta-analysis analyses the results of several studies on a specific topic, in order to find patterns and to generalise the findings. Meta-analyses often use statistical methods.
Systematic literature reviews, on the other hand, can be qualitative or quantitative. They answer a specific (and often new) research question rather than simply summarise the results of other studies.
Benefits of conducting a systematic literature review
There is of course nothing wrong with conducting a ‘regular’ literature review. However, there are several good reasons to conduct a systematic literature review.
First and foremost, it is easy to feel overwhelmed by the amount of literature that is or may be relevant to someone’s research.
Especially master’s and PhD students are easily drawn into the rabbit hole of finding new and relevant literature all the time, feeling insecure and not knowing when to stop looking for more.
A key benefit of conducting a systematic literature review is the knowledge and confidence that all relevant literature has been analysed within certain parameters, reducing the fear that one may have missed something.
Furthermore, by showcasing certain research gaps based on a systematic literature review, the academic relevance of one’s work becomes much stronger.
And being explicit about the methodology of collecting and analysing literature also increases the trustworthiness of one’s statements and arguments.
Academic citation databases suitable for systematic literature reviews
To conduct systematic literature reviews, it is advisable to select a citation database that already has some in-built features to limit search queries.
Google Scholar is a common search engine used by scholars but has only a very simple sidebar to limit search queries. The advantage, however, is that Google Scholar is free to use, even for those who do not have an institutional affiliation.
Web of Science has very elaborate search options. The search engine lets you select between several databases and indexes, such as the Science Citation Index or the Social Science Citation Index. It also lets you search for keywords in a topic or title, for author names, affiliations, years and so forth.
Additionally, Web of Science operates with a high number of Booleans (see the image below on the right) that you can use to specify what you are looking for.
Once Web of Science shows you the search results, you can furthermore filter or organise results according to research areas, discipline, languages, regions, document types and much more.
While it takes some time to learn how to develop targeted search queries on Web of Science, the database’s opportunities for conducting systematic literature reviews are great.
Scopus is the citation database by the publisher Elsevier and has access to more than 36,000 journals. In layout and search options, it is very similar to Web of Science and worth checking out.
Citation databases can also be used in combination. It is advisable to start with one, such as Web of Science and Scopus, but others can be used to double-check that no suitable entries are missed.
Steps for conducting a systematic literature review
Every systematic literature review is different, but there are common steps that most systematic reviews follow:
- Define a research question that is focused and narrow enough.
- Identify keywords that will lead you to articles which can possibly answer your research question.
- Decide on a citation database and develop inclusion and exclusion criteria. Think of a timeframe, discipline, journal, research area, geographical context, etcetera.
- Download all relevant results. This can be hundreds…
- Systematically screen all titles and abstracts. Following your inclusion and exclusion criteria, sort out the irrelevant articles manually.
- Develop your own database of the remaining entries, for instance in excel, and read the remaining entries more thoroughly.
- Start categorising the entries and/or their content in a way that makes sense to answer your research question.
- Create some visual representations of your results and categorisation (for instance in the form of graphs and tables).
- Write down and present your findings in a condensed and engaging way.