This guide is designed for postgraduate students, PhD researchers, and academic staff who need to carry out advanced or systematic literature searches. It includes detailed guidance and examples to support higher-level work.

If you’re new to searching or still building your confidence, we recommend starting with the basics. Understanding the core principles will help you get more from the advanced sections later.

Systematic literature searching involves using databases to find the best available evidence on a topic, following a clear and structured process.

This guide is for anyone who needs to plan and carry out a structured literature search. You might be an undergraduate learning how to search better, a postgraduate choosing a dissertation topic, a PhD student doing a systematic review, or a member of staff working on research, funding, or a Knowledge Transfer Partnership (KTP). This guide gives you clear steps and resources to help you search more effectively.

Systematic searching is different from basic or everyday searching. It follows a structured process to make sure your results are complete, transparent, and reliable. This approach is often used in research to support evidence-based decisions.

Here are the key features of a systematic search:

1. Planned and thorough
   A clear, detailed search strategy (the words you enter into a database) is used to find all relevant evidence across multiple sources. This helps reduce bias and ensures nothing important is missed.
2. Set criteria for including studies
   You decide in advance what kinds of sources will be included or left out - for example, by date, topic, study design, or type of evidence. This keeps the process fair and consistent.
3. Clear and transparent methods
   Every step is recorded - from how you searched, to how you chose sources, to how you analysed them. This makes your work easy to understand and repeat.
4. Checking the quality of evidence
   You look carefully at each source to judge how reliable and relevant it is. This helps you understand how strong the overall evidence is.
5. Bringing the evidence together
   Once you’ve gathered the evidence, you summarise it clearly - highlighting patterns, key findings, and gaps. This helps others draw conclusions or make recommendations.
6. Minimising bias
   By following a set process and avoiding selective choices, systematic searching aims to be fair and balanced.
7. Repeatable and reliable
   Because the method is fully documented, someone else can repeat your search and get similar results. This builds trust in your findings.

Systematic searching sits within the broader planning stage of your research. It helps shape your understanding of the field, define your question more clearly, and build the evidence base for your study. You’ll find it connects closely with support areas like library services for researchers, research design, and literature reviewing.

Getting the basics right gives you a solid foundation - most advanced search techniques are just careful combinations of the core principles. If you're still building confidence, start with our guide How to Search, which covers the essentials clearly.

Take a moment to consider the scope of your project. Thinking clearly about what you’re looking for will help you avoid wasted effort later. Ask yourself:

• Is my topic broad or narrow?
• Do I need recent studies, or a longer historical view?
• Am I interested in international evidence or something more local?
• What kinds of sources will be most useful - journal articles, reports, policy documents, case studies?

Clarifying these points early will help set the boundaries of your search and keep things manageable.

If you're still shaping your research question, exploratory searching can be a useful first step. It gives you a feel for what’s out there and can help you experiment with different keywords or subject terms, spot key debates, authors, or themes in the field, and judge whether your topic is too broad, too narrow, or just right

Finally, it helps to understand how databases actually process your search. Unlike search engines, databases don’t ‘understand’ what you mean - they follow strict logic based on the words you type. They will:

• Look for exact matches or variations of your terms
• Apply any search operators (like AND, OR, NOT)
• Follow rules based on any special syntax (like “quotation marks” or truncation)

Knowing this can make a big difference. If your search isn’t returning what you expect, the issue may not be the content - it might just be the keywords you're using to represent your topic when you search.