Systematic literature review (SLR) is a high-quality evaluation of various databases to answer pre-defined research questions. It is a systematic approach to solving scientific queries based on the secondary data analysis method. For writing a good SLR, a researcher must adopt a step-wise approach to avoid any structuring and ordering challenges. Thus, this article is a step by step guide to write a good SLR even for beginners. This article will first discuss what grey literature is, then it will discuss some short differences between SLR vs LR and end on stating different components of SLR.
1. What is Grey literature?
By definition, grey literature is information produced on all government, academics, business, and industry levels. It may be either in printed or electronic format. Furthermore, grey literature is not always controlled by commercial publishers. This type of literature is often published informally and non-commercially. The grey literature may remain in government reports, statistics and poster forms.
Moreover, the grey literature remains a reliable and good source of information without even being peer-reviewed. Various sources are involved in producing grey literature, but due to lack of indexing or proper organisation, it is not easy to locate them. Thus, grey literature is entirely different from black literature-a peer-reviewed and commercial source of information mainly produced for publication. Many students take it difficult to write and hence get help from masters dissertation writing services.
2. What is the difference between systematic literature review and literature review?
A literature review is a scholarly survey that aims to provide an evidence-based overview of a particular topic. But SLR aims to answer focused research questions by searching, selecting and appraising all high quality and relevant sources of information. A literature review is only an act of summarisation of already published information is a common misunderstanding. However, critical evaluation is another important part of the literature review. Thus, literature review and systematic literature review both are a collection of relevant information to show what has been done in a field and by whom.
In particular, SLR is different from other literature reviews in terms of definitions, purpose, components, requirements, and values.
1. Definition based differences
A systematic literature review is a detailed study of the previous research studies. It is the method to identify, select, synthesise, and appraise the empirical results of a variety of similar studies. But the literature review aims to collect the relevant sources of information and identification of relevant theories, facts and research gaps in order to produce and strengthen the current research. Therefore, SLR and LR both provide information on the same ground but vary in approaches.
2. Goals-based differences
The systematic literature review and literature review also differ greatly on the basis of goals to achieve. In terms of goals, a literature review only works for providing an overview on a topic. But the longer goals of the SLR are to answer focused clinical questions as an effort to eliminate biasness.
3. Question-based differences
The literature review is mostly a part of a dissertation. But the systematic literature review is only part of a dissertation that can withstand alone. The literature review is often based on the general and less specific type of questions in the light of the theories and evidence. At the same time, the SLR answers more clearly defined and answerable clinical research questions. Thus, for SLR some more sophisticated framework for formulating research questions is used.
4. Component-based differences
The systematic literature review can also be differentiated on the basis of structural components. For writing a literature review, one can pick any type of topic of interest and start writing by providing an overview. This type of review often includes Introduction, Methods, Discussion, Conclusion, and Reference list. But SLR is more diversified in terms of components. It needs well-defined inclusion and exclusion criteria, proper identification of keywords and a proper search strategy. More importantly, the identification of the research gap is a common component of both types of research.
5. Requirements based differences
Requirements for systematic literature review include transparency, clarity, integration, focus, coverage, accessibility, and equality. In contrast, the literature review provides an overview to combine all relevant information in one place. Moreover, the former needs more thorough information or research on a topic for search for all the relevant databases, and it is a method of analysis of information. In the latter, information gathered must be relevant to facts for developing a deep understanding of a given topic.
6. Value-based differences
In terms of value, the systematic literature review (SLR) is one step forward than the literature review (LR). The SLR is a qualitative secondary data analysis method. On the other hand, the literature review is the combinatorial approach used to set the stage for data collection and analysis.
Other than the differences based on requirements, value, components, and goals, systematic literature review also differs from the literature review in terms of time and number of authors. SLR completion needs about months to a year or, and on an average, eight months. But LR, due to flexibility in synthesising criteria, can be completed in a few weeks. Also, three to more authors are necessary to publish an SLR, while one author can independently publish LR.
3. What are the different components of a systematic literature review?
Systematic literature review needs a lot of preparation to get started. Thus, before starting it, one must work separately on its different elements to produce a well-impacted review. The following are some important components;
1. Keyword selection and searching
Keyword searching and selection is the most important part of conducting SLR. It aims to streamline the secondary data collection steps.
2. Making an inclusion and exclusion criteria list
This component is necessary to include only specific or highly relevant sources of information in the study.
3. Defining the search strategy
Search strategy aims to describe all methods, databases and other techniques or approaches an individual use to conduct a SLR.
4. Evaluation and synthesis of information
Evaluation and synthesis of facts and figures published in an article is another necessary component of a systematic literature review. It helps researchers in identifying any potential biasness while using the information.
Presentation of information and facts by the name of author and year of publication in the analysis table is the last part of a systematic literature review. After providing all necessary information of selected sources, SLR demands us to use this information to answer all research questions. Consequently, the systematic literature review is a lengthy method to compile highly diverse sources of information in one place.