Here’s a concise glossary of literature searching and retrieval terms useful for researchers working with databases, systematic reviews, and structured searches:

Core Concepts

Types of Searching

Search Building Blocks

 Syntax and Search Logic

Search Management

Search Transparency and Reporting

Other Key Terms

Introduction to Systematic Searching

1. What is a systematic search?
   A structured and comprehensive method of searching for literature, designed to identify all relevant studies on a topic using predefined criteria, and aims to be reproducible, unbiased, and comprehensive.
2. Why is systematic searching important?
   It reduces bias, increases transparency, and ensures replicability in evidence synthesis.
3. How is a systematic search different from a regular literature search?
   Systematic searches use structured strategies across multiple databases and follow strict inclusion/exclusion criteria, unlike informal or narrative reviews.
4. Which databases should I include in a systematic search?
   It depends on your research topic and discipline. Aim to include a mix of subject-specific and multidisciplinary databases. Common choices include Scopus, Web of Science, and subject databases like PsycINFO (for psychology), ERIC (for education), or Business Source Premier (for business). Always choose databases that are relevant to your review question and ensure broad coverage of the literature.
5. What is “grey literature”, and why should I search for it?
   Grey literature includes non-commercial publications like theses, reports, and guidelines. Including it reduces publication bias, but will require some additional effort.
6. How do I use Boolean operators in a search?
   Use AND to combine different components OR to combine synonyms, and NOT to exclude terms. You can combine collections of terms/ lines of search, too, not just single words.
7. How many search terms should I use?
   There’s no fixed number - what matters is that your search captures all relevant synonyms, spelling variations, and related terms for each concept in your question. Use as many as needed to ensure comprehensive coverage, but avoid unnecessary duplication. Having a trusted colleague review your terms can help identify any gaps.
8. How do I translate a search strategy between databases?
   All search strategies are built around the same foundation: keywords. These don’t usually change between databases. What you do need to adapt are the database-specific elements - like syntax (truncation, proximity), field tags, and controlled vocabularies (e.g., MeSH in MEDLINE, Emtree in Embase). Focus on adjusting those while keeping your core textwords consistent.
9. Do I need to use controlled vocabulary terms like MeSH or Emtree?
   Where available, using controlled vocabulary improves precision and helps you find relevant studies indexed under related terminology. Although, it’s important to remember that not all databases or indexes use controlled vocabularies (Scopus, Web of Science indexes), so sometimes keyword searching will have to suffice.
10. Can I just search Google Scholar instead?
    You can, but your search will be incomplete and potentially biased. While Google Scholar can be a useful supplementary source, it lacks transparency, reproducibility, and advanced search functions needed for a systematic search. Consider using the ‘Cited By’ function in Google Scholar as a supplementary search technique instead.

Practical Questions and Helpful Guidance

11. How do I document a systematic search strategy properly?
    Use an Excel spreadsheet with different sheets for your searches, a Word document, or a Text document (like Notepad). Record the databases searched, search strings used, filters applied, and dates searched. PRISMA-S guidelines are helpful here.
12. What is the best way to manage and deduplicate references?
    For most postgraduate projects, a reference manager like Zotero, EndNote, or Mendeley is usually sufficient to organise and deduplicate references. Even Excel can work for smaller reviews with careful manual checking. More advanced tools like Covidence or Rayyan offer automated deduplication and screening features but are typically used in larger or more formal systematic reviews.
13. How often should I update a systematic search?
    Typically every 6–12 months, or before publication. Updates may be needed if your review takes a long time. When updating, run your search from the Accession (or indexing) date - the date records were added to the database - rather than publication date, to ensure you capture newly indexed records (this is why it’s useful to record the “last searched” date in your records..
14. Should I register my review protocol, including my search?
    Yes, if possible. Registering your systematic review protocol (which includes your planned search strategy) on platforms like PROSPERO or OSF helps promote transparency, reduces duplication, and can strengthen the credibility of your work. It's not always required for student projects, but it’s good practice where appropriate.
15. What’s a search filter, and should I use one?
    Filters are pre-tested strategies for specific populations, study types, or methods (e.g., RCTs, qualitative studies). You do not need to use them, but if you choose to, use them carefully!
16. How do I include non-English studies in my search?
    Unless you select an option to include English only records, the database will retrieve records in all languages by default. Avoid language limits in your strategy, and plan for translation at screening or full-text stage if needed.
17. What’s the role of a librarian or information specialist?
    In academic settings, Research Support Librarians and Information Specialists support research students by helping develop clear, structured search strategies, advising on appropriate databases, and reviewing search methods for transparency and rigor. They may also co-author reviews where their input meets authorship criteria, especially in systematic or scoping reviews.
18. Can I use AI tools to generate search strategies?
    It’s best to be very cautious about using AI to create search strategies. Your knowledge of the topic, research question, and relevant literature is essential to developing a robust and reliable search. AI can’t replace that insight, and relying on it risks missing important studies or introducing bias. Use AI, if at all, only as a very rough brainstorming aid - never as a final or standalone solution!

Advanced Topics and Specialist Considerations

19. What is the PRESS checklist?
    Peer Review of Electronic Search Strategies (PRESS) is a tool for evaluating the quality of search strategies.
20. What are adjacency operators and when should I use them?
    Adjacency/proximity operators (e.g., adj3, NEAR/3) allow you to find words near each other - useful for complex concepts.
21. How do I handle polysemy (single word that has multiple related meanings) and homographs (words that are spelled the same but have entirely different, often unrelated meanings) in searching?
    Use context terms, field limits, and proximity operators to avoid irrelevant hits (e.g., “depression” as in mood, not geography).
22. How do I search for qualitative evidence systematically?
    Use specific qualitative filters, index terms (e.g., "interviews," "phenomenology"), and include grey literature sources. Pay close attention to the specific terminology used in qualitative research. However, depending on your topic and search terms, you may not always need separate qualitative filters, sometimes your well-constructed keywords will already capture the qualitative evidence effectively.
23. How can I test the sensitivity and specificity of my search strategy?
    Use a benchmark set of known relevant studies - or key papers and authors you’re certain should be retrieved - to test your search strategy. This helps ensure your search captures all important evidence (sensitivity) without retrieving excessive irrelevant results (specificity).
24. Is it acceptable to use a search strategy from a published review?
    Yes, as a starting point. Using a published strategy can save time and help you identify relevant terms and structures. However, you should always tailor the strategy to your specific research question, adapt it for the databases you are using, and test its performance. It’s also essential to cite and acknowledge the original source of the strategy in your methods or appendices.
25. What if a database doesn’t support controlled vocabulary?
    Rely on keyword searching using title/abstract fields and proximity operators where available.
26. What’s the difference between a systematic review and a scoping review search?
    Scoping searches are often broader and less focused on study quality or design filters. Still systematic, but less restrictive.
27. Should I include preprints in my systematic review?
    Including preprints can be valuable, especially for rapidly evolving or emerging topics where peer-reviewed literature may be limited. However, because preprints have not undergone formal peer review, you should clearly report their inclusion and discuss any limitations this may introduce to the review’s reliability and conclusions.
28. How do I cite or reference my search strategy in a publication?
    You should cite the source of your search strategy directly in-text, for example: “This search strategy was adapted from Smith et al. (2020)”. If the strategy was fully developed by you, you may simply state that it was constructed for the purposes of this review. If the original strategy came from a published review, cite it formally in the reference list.

The following references provide authoritative guidance on the development of search strategies for evidence synthesis. They support the design of transparent, structured, and reproducible search methods appropriate for systematic and scoping reviews, as well as broader evidence-informed enquiry.

Bramer, W. M., de Jonge, G. B., Rethlefsen, M. L., Mast, F. and Kleijnen, J. (2018) 'A systematic approach to searching: an efficient and complete method to develop literature searches', Journal of the Medical Library Association, 106(4), pp. 531-541. Available at: https://doi.org/10.5195/jmla.2018.283. (Accessed: 13 July 2025).

Cooper, C., Garside, R., Varley-Campbell, J., Talens-Bou, J., Booth, A. and Britten, N. (2020) '"It has no meaning to me." How do researchers understand the effectiveness of literature searches? A qualitative analysis and preliminary typology of understandings', Research Synthesis Methods, 11(5), pp. 627-640. Available at: https://doi.org/10.1002/jrsm.1426. (Accessed: 13 July 2025).

Ewald, H., Klerings, I., Wagner, G., Heise, T. L., Stratil, J. M., Lhachimi, S. K., Hemkens, L. G., Gartlehner, G., Armijo-Olivo, S. and Nussbaumer-Streit, B. (2022) 'Searching two or more databases decreased the risk of missing relevant studies: a metaresearch study', Journal of Clinical Epidemiology, 149, pp. 154-164. Available at: https://doi.org/10.1016/j.jclinepi.2022.05.022. (Accessed 13 July 2025).

Grindlay, D. J. and Karantana, A. (2018) 'Putting the 'systematic' into searching - tips and resources for search strategies in systematic reviews', Journal of Hand Surgery (European Volume), 43(6), pp. 674-678. Available at: https://doi.org/10.1177/1753193418778978. (Accessed: 13 July 2025).

Gusenbauer, M. (2022) 'Search where you will find most: Comparing the disciplinary coverage of 56 bibliographic databases', Scientometrics, 127(5), pp. 2683-2745. Available at: https://doi.org/10.1007/s11192-022-04289-7. (Accessed; 12 July 2025).

Hirt, J., Nordhausen, T., Fuerst, T., Ewald, H. and Appenzeller-Herzog, C. (2024) 'Guidance on terminology, application, and reporting of citation searching: the TARCiS statement', BMJ, 385, article number e078384. Available at: https://doi.org/10.1136/bmj-2023-078384. (Accessed; 12 July 2025).

Levay, P., Craven, J. and Lefebvre, C. (2019) Systematic searching [electronic book] : practical ideas for improving results / edited by Paul Levay and Jenny Craven. London: London : Facet Publishing, 2019. (Accessed: 30 June 2025).

MacFarlane, A., Russell-Rose, T. and Shokraneh, F. (2022) 'Search strategy formulation for systematic reviews: Issues, challenges and opportunities', Intelligent Systems with Applications, 15, pp. 200091. Available at: https://doi.org/10.1016/j.iswa.2022.200091. (Accessed: 13 July 2025).

Mathew, M. J. (2024) 'Literature search in systematic reviews: How much is good enough?', Clinical Epidemiology and Global Health, 25, pp. 101485. Available at: https://doi.org/10.1016/j.cegh.2023.101485. (Accessed: 18 May 2025).

Rethlefsen, M. L., Kirtley, S., Waffenschmidt, S., Ayala, A. P., Moher, D., Page, M. J. and Koffel, J. B. (2021) 'PRISMA-S: an extension to the PRISMA statement for reporting literature searches in systematic reviews', Systematic Reviews, 10(1), pp. 1-19.  Available at: https://doi.org/10.1186/s13643-020-01542-z. (Accessed: 28 June 2025).

Stapleton, J., Carter, C. and Bredahl, L. (2020) 'Developing systematic search methods for the library literature: Methods and analysis', Journal of Academic Librarianship, 46(5), pp. 102190. Available at: https://doi.org/10.1016/j.acalib.2020.102190. (Accessed: 1 July 2025).