Boolean Search Operators
Boolean search operators are logical functions—AND, OR, NOT, and parentheses—used to combine and filter search terms in bibliographic databases, library catalogs, and search engines. Named after mathematician George Boole (1815–1864), Boolean logic has been applied to information retrieval since the 1960s. These operators allow researchers to construct complex, precise searches that retrieve only articles meeting specific combinations of criteria, dramatically improving search efficiency and reducing irrelevant results.
Source record
Citations copied verbatim from the method’s source record. No claim-level verification is inferred from them.
- Wilkinson, M. D., Sansone, S. A., Vandervalk, B., & Rocca-Serra, P. (2011). Evaluating information retrieval systems: a guide for researchers. Expert Review of Molecular Diagnostics, 11(2), 181–190. · URL
- Bramer, W. M., Rethlefsen, M. L., Murad, M. H., & Landhuis, E. (2016). When updating systematic reviews, how often should new searches be applied to increase the chance of finding relevant studies? Systematic Reviews, 5(1), 94. · URL
- Sampson, M., Barrowman, N. J., Moher, D., & Klassen, T. P. (2008). Should meta-analysts search Embase in addition to Medline? Journal of Clinical Epidemiology, 56(10), 943–955. · DOI 10.1016/S0895-4356(03)00110-0
Curated claims
Claims persisted in the evidence ledger, each with its own assessment.
This view does not invent a claim assessment when the ledger has none.
Related methods
Generated from the method graph and shown as machine-suggested relations — no evidence claim is inferred.