Literature Review vs. Systematic Review

Attribute	Literature Review	Systematic Review
Definition	A comprehensive survey and analysis of existing literature on a specific topic	A structured and methodical review of literature that follows a predefined protocol
Objective	To gain an understanding of the current state of knowledge on a topic	To answer a specific research question by synthesizing available evidence
Inclusion Criteria	May vary depending on the scope and purpose of the review	Strict criteria are set to include or exclude studies based on predefined characteristics
Search Strategy	May be less systematic and comprehensive	Extensive and systematic search strategy is employed to identify relevant studies
Data Extraction	May involve summarizing key findings or themes from selected literature	Structured data extraction is performed to collect specific information from each study
Quality Assessment	May not always include a formal assessment of study quality	Quality assessment is conducted to evaluate the risk of bias in included studies
Data Synthesis	Findings are often summarized narratively	Data is synthesized using statistical methods (meta-analysis) if appropriate
Publication Bias	May not always assess or report publication bias	Publication bias is considered and addressed if possible

Introduction

When conducting research, it is essential to review existing literature to gain a comprehensive understanding of the topic. Two common methods used for this purpose are Literature Review and Systematic Review. While both approaches involve reviewing published works, they differ in their objectives, methodologies, and the level of rigor applied. In this article, we will explore the attributes of Literature Review and Systematic Review, highlighting their similarities and differences.

Literature Review

A Literature Review is a critical examination and synthesis of existing research and scholarly articles related to a specific topic or research question. It aims to provide an overview of the current state of knowledge, identify gaps, and highlight areas for further investigation. Literature Reviews are often conducted in the early stages of research to establish a theoretical framework and inform the research design.

One of the key attributes of a Literature Review is its flexibility. Researchers have the freedom to select and include studies based on their relevance to the topic, without strict guidelines or predefined criteria. This allows for a broader range of sources to be considered, including books, journal articles, conference papers, and even unpublished works. The focus is on summarizing and synthesizing the findings, arguments, and theories presented in these sources.

Another important aspect of a Literature Review is its subjective nature. Since there are no strict guidelines for inclusion or exclusion, the researcher's expertise and judgment play a significant role in determining which sources to include and how to interpret the findings. This subjectivity can lead to potential bias, as researchers may inadvertently favor studies that align with their own perspectives or preconceived notions.

Furthermore, Literature Reviews often lack a systematic and transparent approach to searching and selecting sources. While researchers may employ various search strategies, such as keyword searches or citation tracking, the process is not as rigorous as in a Systematic Review. This can result in the omission of relevant studies or the inclusion of studies that may not meet the highest standards of quality.

Despite these limitations, Literature Reviews serve a valuable purpose in research. They provide a broad overview of the existing literature, help identify gaps in knowledge, and offer insights into the current state of research on a particular topic. They are particularly useful when exploring emerging or interdisciplinary fields where limited research has been conducted.

Systematic Review

A Systematic Review, on the other hand, is a rigorous and structured approach to reviewing literature. It aims to identify, evaluate, and synthesize all available evidence relevant to a specific research question. Systematic Reviews follow a predefined protocol that outlines the search strategy, inclusion and exclusion criteria, and methods for data extraction and analysis.

One of the key attributes of a Systematic Review is its comprehensive and unbiased nature. Researchers strive to include all relevant studies, regardless of their publication status or language. This is achieved through a systematic and transparent search process, which often involves searching multiple databases, screening titles and abstracts, and assessing the full texts of potentially eligible studies.

Moreover, Systematic Reviews employ strict inclusion and exclusion criteria to ensure the highest level of methodological quality. These criteria may include study design, sample size, data collection methods, and statistical analysis. By applying these criteria consistently, researchers aim to minimize bias and increase the reliability of the findings.

Another important aspect of a Systematic Review is the synthesis of data. Unlike Literature Reviews, which often rely on narrative summaries, Systematic Reviews employ statistical techniques, such as meta-analysis, to combine and analyze the results of multiple studies. This allows for a more objective and quantitative assessment of the evidence, providing a clearer picture of the overall effect or association being investigated.

However, conducting a Systematic Review can be a time-consuming and resource-intensive process. The comprehensive search, screening, and data extraction require a significant investment of time and expertise. Additionally, the strict inclusion criteria may result in a smaller pool of eligible studies, limiting the generalizability of the findings.

Similarities and Differences

While Literature Review and Systematic Review differ in their objectives and methodologies, they also share some similarities. Both approaches involve reviewing existing literature to gain insights into a specific topic or research question. They require a thorough understanding of the subject matter and the ability to critically evaluate the quality and relevance of the sources.

Furthermore, both Literature Review and Systematic Review contribute to the knowledge base of a particular field. They help researchers identify gaps in knowledge, highlight areas for further investigation, and inform the development of new research projects. They also play a crucial role in evidence-based practice, providing practitioners with a synthesis of the current evidence to inform decision-making.

However, the key difference lies in the level of rigor and transparency applied. While Literature Reviews offer flexibility and subjectivity in source selection and interpretation, Systematic Reviews follow a predefined protocol and employ strict criteria to ensure the highest level of methodological quality. Systematic Reviews also utilize statistical techniques for data synthesis, providing a more objective and quantitative assessment of the evidence.

Conclusion

In conclusion, Literature Review and Systematic Review are two distinct approaches to reviewing existing literature. While Literature Reviews offer flexibility and subjectivity, Systematic Reviews provide a rigorous and transparent methodology. Both approaches contribute to the knowledge base of a particular field, but Systematic Reviews offer a higher level of methodological rigor and objectivity. Researchers should carefully consider the objectives of their study and the available resources when deciding which approach to adopt. Ultimately, the choice between Literature Review and Systematic Review depends on the research question, the desired level of rigor, and the available time and resources.