What is Literature Review? Definition, Types and Examples (1000 to 1400 words)
Definition
In research, every study begins with a question, but before answering it, you must understand what others have already discovered. This process is called a literature review.
A literature review is more than just a summary of books and papers. It’s a critical evaluation of existing research that shows where knowledge stands, what is missing, and how your study contributes something new. Without a proper literature review, research becomes directionless.
Types of Literature Reviews
Different types of literature reviews serve different purposes. Let’s explore the most common types used in academic writing and publications.
Narrative (Traditional) Literature Review
This is the most common and simple type. It gives a broad overview of a topic without following a strict research process.
- Purpose: To summarize what is already known.
- Example: “A review of various natural adsorbents used for wastewater treatment.”
- Best for: Early-stage researchers, essays, and background studies.
Systematic Literature Review (SLR)
This is a structured and scientific method of reviewing research. It follows clear steps defining keywords, selecting databases, setting inclusion/exclusion criteria, and analyzing results systematically.
- Purpose: To provide an unbiased and comprehensive understanding of all research on a specific question.
- Example: “A systematic review of microplastic removal technologies between 2015–2024.”
- Best for: Journal publications and postgraduate thesis.
✅ Tips to remember: Use tools like PRISMA flow diagrams to show your selection process.
Scoping Review
A scoping review is broader than a systematic review.
Instead of focusing on one research question, it explores the overall range and nature of research in a field.
- Purpose: To map what research has been done and identify knowledge gaps.
- Example: “A scoping review of biochar applications in environmental remediation.”
- Best for: Emerging or less-studied topics.
Theoretical Literature Review
This review focuses on theories, frameworks, and models rather than data or experiments.
It explains the main theoretical ideas that guide research.
- Purpose: To analyze and compare existing theories.
- Example: “A theoretical review of customer trust models in online platforms.”
- Best for: Conceptual papers or Ph.D. proposals.
Integrative Literature Review
This type combines both experimental and theoretical studies to generate new frameworks or perspectives.
- Purpose: To synthesize past findings and propose a new understanding.
- Example: “An integrative review of AI-based personalization and its effect on consumer trust.”
- Best for: Advanced researchers developing new models or frameworks.
Meta-Analysis
A meta-analysis uses statistical methods to combine results from multiple studies.
It’s often used in medical, biological, or social science research to identify overall trends.
- Purpose: To find patterns or general conclusions from many studies.
- Example: “A meta-analysis of the effectiveness of yoga in reducing anxiety.”
- Best for: Quantitative research fields.
Steps to Write a Literature Review
Choose and Define Your Topic
Select a focused research area.
Avoid very broad topics, such as “climate change,” and narrow them down, such as “the role of biochar in reducing carbon emissions.”
Then write your research question clearly, such as:
“How effective is biochar in reducing carbon emissions from agricultural soil?”
Search for Relevant Literature
Use reliable databases like:
- Google Scholar
- Scopus
- ScienceDirect
- PubMed
- Web of Science
Use keywords and Boolean operators (AND, OR, NOT) to refine your search.
Example: “biochar AND microplastics AND removal.”
Evaluate and Select Sources
Not every paper you find is relevant or high quality.
Choose:
- Peer-reviewed articles
- Recent publications (past 5 years)
- Studies that directly relate to your question
Avoid unreliable websites, blogs, or outdated sources.
Read and Take Notes
While reading, note down:
- Main findings
- Research methods used
- Limitations
- Connections between studies
Organize by Themes or Concepts
Group your findings into themes, not by author names.
Example themes could be:
- Sources of microplastics
- Biochar preparation methods
- Removal efficiency and limitations
This makes your review organized and easy to follow.
Analyze and Synthesize
Example:
“While earlier studies (A, B) reported positive results under controlled conditions, recent research (C, D) suggests these findings may not hold true in real environments.”
Identify the Research Gap
This is the most important part of your review. A research gap is the missing knowledge of your study.
Example:
“Most studies on biochar have focused on water systems, with limited investigation of its performance in soil environments. The current study aims to address this gap.”
Write and Cite Properly
Use academic language and correct referencing style (APA, MLA, or Harvard). Avoid plagiarism by paraphrasing in your own words.
Correct format:
“Biochar has emerged as a sustainable material for pollutant removal (Li et al., 2023).”
Examples of Literature Review Topics
Here are some examples of topics suitable for literature reviews across disciplines:
🧬 Science & Environment
- The impact of biochar on soil fertility
- Nanotechnology in wastewater treatment
- Climate change and agricultural productivity
💻 Technology
- AI in healthcare diagnostics
- Blockchain and data privacy
- Machine learning in education
🧘 Health & Psychology
- The effectiveness of yoga on stress reduction
- Mindfulness and emotional well-being
- Sleep patterns and mental health
📊 Business & Management
- Customer loyalty in digital marketplaces
- Corporate social responsibility and brand reputation
- The influence of leadership styles on employee performance
Common Mistakes to Avoid
- Summarizing without analysis – Don’t just list studies. Compare them.
- Using outdated papers – Focus on recent research.
- Poor organization – Use subheadings for clarity.
- Ignoring the research gap – Always show what’s missing.
