Literature reviews play a crucial role in research, serving as a foundation for scholarly and scientific inquiry and knowledge advancement. This intensive evaluation of previously written literature gives researchers a deeper understanding of the current progress of knowledge in their field. Understanding the different types of literature reviews is crucial for PhD students and early career researchers aiming to conduct highly professional and deeply researched academic work. We will explore why we do literature reviews, give an overview of the different types of literature reviews, and discuss what factors to consider when selecting the right kind in this article.
Purpose and significance of literature reviews
Literature reviews serve multiple purposes in research. Firstly, they help researchers find where gaps in the research are, then place their work within the existing body of knowledge. By combining existing research, literature reviews allow researchers to identify niches that require further investigation and contribute to the refining of research questions and objectives. Importantly, literature reviews provide a comprehensive view of past research undertaken on a subject. This helps researchers to build upon established theories and findings and avoid duplicating previous work. It also offers researchers essential guidance on methodologies used in previous studies. Researchers can use these insights to determine appropriate methods for their research and avoid repeating past pitfalls. Finally, literature reviews are used to help identify key trends, controversies, and debates within a particular field. This leads to critical analysis and hypothesis formation.
3 Types of literature reviews
There are three main types of literature reviews commonly used in academic and scientific research: narrative reviews, systematic reviews, and meta-analyses. Each type has its own approach and objectives.
Narrative Reviews
Sometimes also referred to as traditional literature reviews, this type of literature review helps researchers to gather information and add to existing research on a specific topic. Narrative reviews are usually descriptive and often rely on the expertise and judgment of researchers to analyze and interpret the findings of research. It provides a broad overview of a subject’s development. It is valuable when exploring new, innovative, complex, and emerging areas of research, allowing researchers to capture a broad range of perspectives and theories. This type of literature review, however, has a potential for bias and lacks statistical analysis.
Systematic Reviews
This type of literature review offers a more rigorous and structured approach to research. When undertaking a systematic literature review, researchers usually use a predefined set of “inclusion” and “exclusion” criteria to ensure that the reviewed literature is unbiased and representative of the research question. By comparing the findings of multiple studies with each other, systematic reviews give a comprehensive and objective summary of the reviewed literature for the research paper. Systematic reviews are beneficial for addressing niche research questions and getting recommendations based on evidence. However, this type of literature review is time and resource-intensive and may exclude some relevant studies due to strict inclusion criteria.
Meta-analysis
Meta-analysis is a statistical technique used to take inputs from multiple studies of varying biases to come to a unique conclusion. It aims to bring a birds-eye view of several studies individually and get a sense of the overall picture from this. Meta-analysis maintains neutrality through numbers, as a greater number of sources means more neutrality. This type of literature review is useful when there are contradictions within the findings of different studies by different researchers. There is one drawback, however: this type of literature review requires a sufficient number of comparable studies, potential for publication bias and complex statistical analysis.
Factors to consider when choosing the appropriate type of literature review
When selecting the most appropriate type of literature review, researchers should consider several factors, including the research question or objective, available resources (such as time and budget), the scope of the topic, and the desired level of depth and rigour. As an example, traditional literature reviews are best for research on exploratory or broad topics, as they provide several perspectives that can impact research because of how it is viewed. Similarly, systematic reviews are ideal when the aim is well-defined, and there is a need for a rigorous evaluation of evidence.
Irrespective of the type of literature review used, the fact remains that it is an integral part of research as it provides researchers with a strong foundation based on existing knowledge and helps them identify research gaps. Understanding different types of literature reviews will help researchers ensure that their work is deeply researched and credible.
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