Difference Between Literature Review And Systematic Review
In academic research, literature reviews and systematic reviews stand out as essential components, each playing a unique role in advancing scholarly understanding. As researchers dive into the complexities of their fields, the need to synthesise existing knowledge becomes paramount. It helps them in developing research strategies and carry on with the research.
Unlike other types of reviews, literature reviews often adopt a narrative approach, presenting a cohesive summary of the current state of knowledge within a given field. They serve as a foundation for understanding the historical context, key concepts, and debates surrounding a subject.
The goal of a systematic review is to provide an unbiased, comprehensive synthesis of all relevant evidence to answer a specific research question. This approach ensures transparency, replicability, and a minimised risk of bias in the review process.
Importance Of Both Types Of Reviews In Research
The importance of literature reviews and systematic reviews in research cannot be overstated. They serve complementary roles, contributing significantly to advancing knowledge and the research process.
Literature reviews are crucial for establishing a foundational understanding of a subject. By surveying and synthesising a diverse array of sources, they help researchers identify gaps, patterns, and trends in existing literature. Literature reviews provide context, allowing scholars to position their work within the broader academic discourse and discern ideas’ evolution over time.
Systematic reviews, on the other hand, are vital for evidence-based decision-making. Through their rigorous methodology, systematic reviews offer a robust and objective assessment of the available evidence on a specific research question.
Policymakers, clinicians, and researchers rely on systematic reviews to inform their decisions, confident in the systematic and unbiased approach employed in synthesising evidence.
Let’s explore both terms in detail now.
At the heart of academic inquiry, the literature review is a comprehensive exploration and synthesis of existing scholarship related to a specific research question or topic. Its primary purpose is to provide a better understanding of the current state of knowledge, offering researchers a foundational platform to build their studies.
It has the following characteristics.
A distinctive feature of a literature review is its expansive scope and rapid review. Unlike more focused research inquiries, a literature review casts a wide net, encompassing various sources. This inclusivity allows researchers to gain a holistic perspective on the subject, identifying key themes, theories, and methodologies contributing to the topic’s broader understanding.
Inclusion Of Various Sources
Literature reviews draw from a rich tapestry of managing sources, including scholarly articles, books, conference papers, and other relevant materials. This multidisciplinary approach ensures a well-rounded exploration of the topic, capturing insights from various disciplines and perspectives. By tapping into a variety of sources, a literature review aims to present a comprehensive overview of existing knowledge.
The synthesis in a literature review is often presented in a narrative form. Rather than employing a structured statistical analysis common in systematic reviews, a literature review weaves together the findings and insights from analysing sources into a cohesive narrative.
This narrative synthesis allows for the exploration of the evolution of ideas, conflicting viewpoints, and emerging trends within the chosen field of study.
Goals Of A Literature Review
There are several reasons for performing a literature review, including the following:
Identifying Gaps In Existing Research
One of the primary objectives of a literature review is to discern gaps or limitations in the current body of knowledge. By critically examining existing literature, researchers can identify areas where further investigation is warranted.
This gap identification process sets the stage for formulating new research questions and exploring uncharted territory within a given field.
Providing Background And Context
A literature review is a historical and contextual backdrop for a research study. It offers readers a comprehensive understanding of developing ideas and theories related to the research topic.
This historical context is crucial for researchers to position their work within the broader academic conversation, showcasing the evolution of thought and the intellectual journey that has led to the current state of understanding.
Summarising And Evaluating Existing Literature
Through systematic summarisation and evaluation, a literature review distils complex information into manageable insights. Researchers summarise key findings and evaluate sources and previous studies’ methodological rigour, strengths, and weaknesses.
This critical assessment aids in determining the reliability and validity of existing research, informing the approach and methodology of the researcher’s own study.
In evidence-based research, the systematic review stands as a gold standard for synthesising existing knowledge transparently and rigorously. Unlike the more narrative approach of literature reviews, systematic reviews adhere to a structured methodology designed to minimise bias and produce a comprehensive summary of available evidence.
These are the main characteristics of a systematic review.
Researchers follow a meticulously planned process, employing explicit and well-defined steps to ensure the reliability and validity of the review. This methodological rigour distinguishes systematic reviews from other review types, underlining their commitment to a disciplined and principled approach.
Predefined Criteria For Inclusion/ Exclusion
Systematic reviews operate within clearly established criteria for including or excluding studies. These criteria are predefined and explicitly stated in a protocol before the review begins, ensuring transparency and minimising the risk of bias.
The inclusion/exclusion criteria typically consider factors such as study design, participant characteristics, and intervention specifics, among others, to maintain a focused and relevant selection of studies.
Transparent And Replicable Process
Transparency is a hallmark of systematic reviews. Every step of the review process, from the initial search strategy to data extraction and analysis, is documented thoroughly and made accessible.
This transparency not only enhances the credibility of the review but also facilitates replication by other researchers. By adhering to a transparent and replicable process, systematic reviews contribute to the cumulative nature of scientific knowledge.
Goals Of A Systematic Review
Some of the goals of conducting systematic reviews are listed below.
Summarising Existing Evidence Systematically
The primary goal of a systematic review is to provide a comprehensive and systematic summary of the existing evidence on a specific research question. By synthesising data from multiple studies, systematic reviews go beyond individual findings, offering a consolidated overview that can uncover patterns, trends, and inconsistencies in the body of literature.
Minimising Bias Through A Structured Approach
Systematic reviews prioritise the reduction of bias throughout the review process. The strict adherence to predefined criteria, rigorous methodology, and transparent documentation minimises the risk of selective reporting and ensures that all relevant evidence, regardless of its findings, is considered.
This commitment to a structured and unbiased approach enhances the credibility and reliability of the review’s conclusions.
Informing Evidence-Based Decision-Making
Perhaps the most significant contribution of a systematic review is its role in informing evidence-based decision-making. Policymakers, clinicians, and researchers rely on systematic reviews as a trustworthy source of synthesised evidence.
By presenting a balanced and comprehensive overview, systematic reviews empower decision-makers to make informed choices grounded in the best available evidence, ultimately enhancing the quality of interventions, policies, or practices.
Key Differences Between Systematic and Literature Reviews
The major differences between the two reviews are discussed below.
A. Research Question And Focus
- Literature Review: Broader Research Questions
Literature reviews typically address broad and overarching research questions. Their aim is to provide a comprehensive overview of existing knowledge within a particular field or on a specific topic. By exploring a wide range of sources, literature reviews seek to establish a foundational understanding and identify key themes, trends, and gaps in the literature.
- Systematic Review: Specific Research Questions
In contrast, systematic reviews focus on addressing specific, well-defined research questions. These questions guide the systematic review process, shaping the inclusion criteria for studies and determining the overall scope of the review.
The specificity of the research question is a defining characteristic of systematic reviews, allowing for a targeted and exhaustive examination of the available evidence.
- Literature Review: Less Structured, More Narrative
Literature reviews adopt a less structured approach, emphasising a narrative synthesis of existing literature. While researchers follow a general methodology for searching and reviewing the literature, the process allows for flexibility and interpretation.
The narrative style enables the exploration of historical developments, theoretical perspectives, and diverse viewpoints within the chosen field.
- Systematic Review: Structured, Follows a Predefined Protocol
Systematic reviews adhere to a highly structured and predefined methodology. Before initiating the review, researchers develop a protocol outlining the review’s objectives, search strategy, inclusion/exclusion criteria, and analysis methods.
This structured approach ensures transparency, repeatability, and minimises the risk of bias in the selection and interpretation of studies.
C. Inclusion of Studies
- Literature Review: Inclusive of Various Study Types
Literature reviews include a wide range of study types, including qualitative and quantitative research, theoretical papers, and empirical studies. The inclusive nature allows for a holistic exploration of the topic, incorporating diverse perspectives and methodologies present in the existing literature.
- Systematic Review: Inclusion Based on Strict Criteria
Systematic reviews employ strict inclusion and exclusion criteria carefully defined in the review protocol. These criteria are designed to ensure that only studies meeting specific standards are included in the review. This selective approach contributes to the reliability and validity of the systematic review’s findings.
D. Data Synthesis
- Literature Review: Narrative Synthesis
The synthesis of data in a literature review is often presented in a narrative format. Researchers weave together findings from different sources, providing a comprehensive and qualitative summary of the existing literature. The narrative synthesis allows for the exploration of relationships, trends, and patterns within the literature.
- Systematic Review: Meta-analysis or Statistical Synthesis
Systematic reviews often involve a quantitative synthesis of data, known as meta-analysis. This statistical approach combines data from multiple studies to generate quantitative conclusions. The emphasis on quantitative synthesis distinguishes systematic reviews, offering a more objective and numerical representation of the overall effect or association within the body of evidence.
|To answer a specific research question using a rigorous, predefined methodology.
|To provide a comprehensive overview of existing literature on a broad topic without a specific research question.
|Clearly defined and focused on a specific topic or issue.
|Broad and may not be as clearly defined, covering a general area of interest.
|Follows a structured and transparent process, including systematic search, inclusion/exclusion criteria, and quality assessment of studies.
|Less structured, may involve a narrative synthesis of literature without a predefined method for study selection.
|Inclusion and exclusion criteria are predefined and applied systematically to identify relevant studies.
|Studies are selected based on relevance to the topic, but criteria may be less strict and more subjective.
|A meta-analysis or systematic synthesis of findings from selected studies, aiming for an objective summary of evidence.
|Often involves a narrative synthesis, summarising and discussing findings without statistical analysis.
|Strives to minimise bias through a systematic approach to study selection and data extraction.
|May not have the same level of rigor in minimising bias, and selection criteria can be more subjective.
|Efforts are made to identify and address publication bias, such as searching for unpublished studies.
|May be less focused on identifying and addressing publication bias.
|Conclusions are based on the synthesis of high-quality evidence and are more likely to be generalisable.
|Conclusions may be more interpretive and subjective, based on a broader range of literature.
|Typically more time-consuming due to the systematic and comprehensive nature of the review.
|Generally faster, as it involves summarising existing literature without the same level of detailed analysis.
While there are many differences between literature review and systematic review, there are some similarities as well.
A. Both Involve A Thorough Search Of Existing Literature
Both literature reviews and systematic reviews share a foundational step in their process: an extensive and systematic search of existing literature. This involves identifying and gathering relevant studies, articles, books, and other scholarly materials related to the chosen research question or topic.
The comprehensive search is crucial for ensuring that the review is inclusive and representative of the breadth of existing knowledge.
B. Both Contribute To The Understanding Of A Specific Topic
Despite their methodological differences, both literature reviews and systematic reviews contribute significantly to the understanding of a specific topic within a particular field.
By synthesising and analysing existing literature, these reviews provide researchers and readers with a comprehensive overview of the current state of knowledge, key debates, and trends in the chosen study area. This shared objective underscores the importance of both review types in advancing scholarly understanding.
C. Both Play A Crucial Role In Research And Academic Writing
Literature reviews and systematic reviews are integral components of the research and academic writing process. They serve as essential tools for scholars, researchers, and students alike, guiding them through the existing knowledge landscape.
These reviews help researchers situate their work within the broader context of their field, identify gaps in knowledge, and establish a foundation for new research questions. In academic writing, both literature and systematic reviews contribute to developing a robust theoretical framework, providing the necessary context for the research study.
Both review types are valuable resources for readers seeking to gain insights into a specific subject. They offer a synthesis of existing literature that is accessible and comprehensible, making complex topics more manageable for a diverse audience. As such, literature reviews and systematic reviews play a pivotal role in shaping the scholarly conversation and facilitating the dissemination of knowledge within academic communities.
When To Use Each Type
Here is a guide on when it is best to use either of the types of reviews.
Situations Favouring A Literature Review
You can use literature reviews in these cases.
Literature reviews are particularly well-suited for exploratory research endeavours. When researchers aim to gain a broad understanding of a topic, identify key concepts, and explore various perspectives within a field, a literature review provides the flexibility needed for this initial exploration.
The narrative synthesis allows researchers to delve into diverse sources and lay the groundwork for more focused inquiries.
Broad Overviews Of A Topic
In situations where the goal is to provide a comprehensive and holistic overview of a subject, a literature review is the preferred choice. Whether compiling historical developments, theories, or methodologies, literature reviews excel in presenting a broad perspective.
This makes them invaluable for academic writing aiming to establish context, trace the evolution of ideas, and highlight the diversity of thought within a given field.
Situations Favouring A Systematic Review
Some ways where a systematic review might help include the following.
Addressing Specific Research Questions
Systematic reviews are ideal when researchers have specific, well-defined research questions that require a focused and exhaustive examination of existing evidence.
The rigorous methodology of systematic reviews ensures that all relevant studies are considered, allowing for a meticulous analysis of the available evidence to answer targeted research questions. This approach is particularly beneficial when precision and specificity are paramount.
Assessing The Overall State Of Evidence On A Topic
When the goal is to assess and synthesise the overall state of evidence on a particular topic, a systematic review is the preferred choice. Systematic reviews are valuable for consolidating data from multiple studies, providing a comprehensive overview beyond individual findings.
This is especially important in fields where evidence-based decision-making is crucial, as systematic reviews offer a high level of reliability in assessing the cumulative body of evidence.
Frequently Asked Questions
A literature review provides a broad summary of existing literature on a topic, lacking a specific methodology. In contrast, a systematic review follows a structured process, rigorously selecting, appraising, and synthesising studies to answer a focused research question, aiming for an objective and comprehensive summary of evidence.
A literature review is considered systematic if it employs a well-defined methodology, including a systematic search, predefined inclusion/exclusion criteria, and a transparent process for study selection, data extraction, and synthesis. Systematic reviews aim for objectivity, minimising bias, and providing a rigorous summary of relevant evidence on a specific research question.
A literature review summarises existing research on a topic, encompassing various types of sources. A studies review specifically focuses on summarising and critiquing individual research studies. While a literature review is broader, a studies review delves deeper into the details of selected studies, often evaluating their methodologies and findings.
An example of a systematic review is a comprehensive analysis of multiple studies on the effectiveness of a particular medical intervention, such as “Systematic Review of Randomised Controlled Trials Assessing the Efficacy of Antibiotics in Treating Acute Sinusitis.” It follows a structured methodology to synthesise and evaluate the available evidence.
The purpose of a systematic review is to provide a rigorous and transparent synthesis of existing evidence on a specific research question. It involves a systematic search, critical appraisal, and synthesis of relevant studies, aiming to minimise bias and offer an objective summary to inform decision-making in various fields, such as healthcare or social sciences.