I’ve noticed that new PhD students often mix up literature reviews and related work sections. They’re actually quite different, though. Let me explain.
Think of a literature review as a deep dive into everything we know about a topic. It stands on its own. It’s a standalone document that systematically examine the current state of knowledge on a particular topic.
In my experience, literature reviews usually show up as chapters in theses or as standalone papers. They’re detailed and evaluate existing research thoroughly. Most of my students spend weeks or sometimes even years synthesizing all the studies on their relevant topic in their dissertation chapters. Consider this a research methodology with its own systematic approach, quality criteria, and contribution to knowledge. It follows rigorous protocols for searching, selecting, analyzing, and synthesizing research. Some literature reviews can be entire dissertations by themselves, and the best ones actually generate new theoretical insights or practical recommendations.
Related work sections, on the other hand, are more like targeted summaries that go in research papers. When I write these, I only focus on studies that directly connect to my specific research question. This section positions your research within the existing body of knowledge. I usually summarize what others have done and explain how my work fills a gap. Think of it as the context-setting for your specific research question. You’re not trying to be comprehensive — you’re being strategic about which studies to include based on their direct relevance to your work.
The key differences come down to size, detail, and goal. I’ve found that literature reviews paint the big picture of a research area. They help us spot what’s missing and build a strong foundation for our work. On the flip side, related work sections just show we’ve done our homework and explain why our new research matters.
Think of it like this: A literature review is like a detailed map of an entire city, while a related work section is more like directions to a specific restaurant. I’ve seen many students get confused about which one to use. Knowing the difference helps you pick the right tool for your academic writing project.
The key difference: related work serves your research, while a literature review is research.
Most PhD students default to the wrong literature review type
When PhD students do decide to conduct a formal literature review, they almost always gravitate toward what they think is a systematic review because it sounds the most rigorous.
But here’s the problem: Systematic reviews require exhaustive searching, formal quality assessment protocols, and often take 12–18 months to complete properly. They’re designed to answer specific clinical or policy questions with clear inclusion/exclusion criteria. If your research question is broader, more exploratory, or theoretical in nature, a systematic review might actually limit your ability to make meaningful contributions.
For example, if you’re exploring an emerging technology area where there aren’t many high-quality empirical studies yet, insisting on systematic review criteria might leave you with too few papers to analyze meaningfully. You’d be better served by a scoping review or mapping review that can capture the breadth of available literature and identify research gaps.
The key is matching your review type to your research goals, not just choosing what sounds most impressive.
The 14 literature review types you need to know
1. Critical Review: Demonstrates you’ve extensively researched literature and critically evaluated its quality, going beyond description to include analysis and conceptual innovation. Perfect for theoretical contributions.
2. Literature Review: The generic umbrella term for examining published literature, which can vary widely in scope and comprehensiveness. Often what students write without realizing there are more specific alternatives.
3. Mapping Review/Systematic Map: Maps out and categorizes existing literature to identify gaps and inform future research. Ideal when you need to understand the landscape of a research area.
4. Meta-Analysis: Statistically combines results from quantitative studies to provide more precise effect estimates. Essential when you have multiple studies measuring the same outcomes.
5. Mixed Studies Review: Combines quantitative and qualitative research evidence, useful when your research question requires both types of evidence to answer comprehensively.
6. Overview: Provides a broad summary of literature, often used synonymously with other review types but typically less rigorous in methodology.
7. Qualitative Systematic Review: Integrates findings from qualitative studies by looking for themes and constructs across studies, perfect for understanding experiences or phenomena.
8. Rapid Review: Uses systematic review methods but within time constraints, trading some comprehensiveness for faster turnaround. Great for preliminary assessments.
9. Scoping Review: Provides preliminary assessment of literature scope and size, identifying the nature and extent of research evidence. Excellent for exploring emerging areas.
10. State-of-the-Art Review: Addresses current matters and cutting-edge developments, often offering new perspectives or identifying future research directions.
11. Systematic Review: The gold standard for evidence synthesis, using rigorous methods to search, appraise, and synthesize research evidence according to established guidelines.
12. Systematic Search and Review: Combines critical review elements with comprehensive search processes, producing “best evidence synthesis” for broad questions.
13. Systematized Review: Attempts to include systematic review elements but falls short of full systematic review rigour, often used for student assignments.
14. Umbrella Review: Compiles evidence from multiple reviews into one accessible document, focusing on broad conditions with competing interventions.
Choose your review type based on your research goals
The biggest mistake PhD students make is choosing their literature review type based on what they think their supervisor wants to see or what they think is the strictest approach, rather than what actually serves their research questions. Don’t make this mistake.
If you’re trying to map out an emerging field, don’t force yourself into a systematic review framework that requires you to exclude perfectly relevant papers because they don’t meet arbitrary quality criteria. If you’re building theory, a critical review might serve you better than a scoping review. If you’re informing practice, a rapid review might be more appropriate than spending two years on a deep systematic review.
Here’s my easy recommendation: Start by clearly articulating what you want your literature review to accomplish. Are you trying to identify gaps? Build theory? Inform methodology? Answer a specific question? Once you’re clear on your purpose, the right review type becomes obvious.
Keep in mind that your literature review should demonstrate your expertise in the field and contribute something valuable to the conversation. Don’t treat it like a checkbox on your thesis requirements.
Methodology matters more than you think
Your choice of literature review type will determine everything from your search strategy to your analysis methods to the claims you can make about your findings.
Don’t just default to writing related work when you could be conducting a rigorous literature review that becomes a significant contribution in its own right. And definitely don’t choose a review type just because it sounds impressive. Choose the one that actually serves your research goals and timeline.
The best PhD students understand that their literature review is an opportunity to demonstrate methodological sophistication, not just summarize what other people have done.
Now get out there and choose your literature review type strategically. You got this.
