Boolean Operators and Advanced Search Techniques

Not every task needs advanced techniques. But they’re worth using when:

• You get too many irrelevant results

• You can’t find enough sources

• You’re searching in a large or complex database

• You need to show a structured, repeatable search strategy

• You’re doing a dissertation, literature review, or PGR-level work

Boolean operators are special words (AND, OR, NOT) that help you control how search tools combine your keywords.

• AND – narrows results by combining different ideas (e.g. anxiety AND sleep)

• OR – broadens results by including synonyms (e.g. teenager OR adolescent)

• NOT – excludes results with specific terms (e.g. stress NOT workplace)

Use NOT carefully. It can exclude a relevant source simply because the unwanted term appears somewhere in the fields being searched. Check what you lose before keeping the exclusion.

Tip: Always use uppercase (AND, OR, NOT) — many search tools expect it.

Use double quotation marks to search for an exact phrase.

Examples:

• "climate change"

• "data protection"

• "corporate social responsibility"

Without quotation marks, the search tool may treat the words separately.

Tip: Use phrase searching to make your results more precise.

Use brackets to group terms and control the logic of your search.

Example:

• (anxiety OR stress) AND sleep

This tells the database to find sources that mention either anxiety or stress — but also include sleep.

Without brackets, your search may run in the wrong order.

Tip: Brackets help especially when combining OR with AND.

Psychology
(anxiety OR depression) AND "young adults"

Business
("corporate social responsibility" OR CSR) AND marketing

Computing
AI AND ethics AND (bias OR fairness)

Health Sciences
("patient safety" OR "clinical risk") AND hospitals

Law
("human rights" OR "civil liberties") AND surveillance

Truncation helps you find words beginning with the same letters. Many databases use an asterisk * after a word stem.

Examples:

• educat* can find education, educating and educator
• comput* can find computer, computing and computational

Wildcards can replace characters within a word. In LibrarySearch, ? represents exactly one character: wom?n can find woman and women.

To include both UK and US spellings of colour, you can use color OR colour.

Symbols and rules vary between search tools. Check the service’s help before using truncation or wildcards.

Some databases let you search for words appearing close together, without requiring an exact phrase.

Examples in EBSCO databases:

• climate N3 crisis searches for the words within three words of each other, in either order
• leadership W5 innovation searches for the words within five words of each other, with leadership appearing first

Enter these expressions without quotation marks around the whole search.

Different services use different proximity operators and distance rules. Follow the help for the service you are using rather than copying syntax from another database.

If a search produces unexpected results, check how the search tool is interpreting your terms:

• check that it recognises the operators and symbols you have used
• group alternatives joined by OR within brackets when combining them with other concepts
• check whether quotation marks are restricting an important phrase too closely
• check that your truncation or proximity syntax is supported
• review any NOT exclusions that may be removing relevant material

Change one part of the search at a time and compare the results.

For broader advice on search terms, filters and choosing another search route, see Search effectively.

A field is a particular part of a search record, such as its title, author or abstract. Advanced Search often lets you choose which field to search.

Depending on the service, you might:

• search the Title field to focus on publications whose titles mention your concept
• search the Abstract field to look within summaries of publications
• search the Author field to find work by a particular researcher

For example, try searching for "social media" in the Title field. Compare the results with a broader search. A title search may exclude relevant publications that use different wording in their titles.

Available fields and their names vary. Check the service’s help to understand what each option searches.

Use this basic template to construct your own advanced search:

("first keyword" OR synonym) AND ("second keyword" OR synonym)

Examples:

• (stress OR anxiety) AND (university OR "higher education")

• (ethics OR fairness) AND AI AND hiring

Keep a copy of useful search strings so that you can revisit or adapt them. For guidance on recording searches and an example log, see Search effectively. Follow your programme or supervisor’s requirements where a documented search is required.

If your assessment permits it, AI tools can help you:

• suggest possible keywords and synonyms

• explain Boolean operators and other search techniques

• draft search strings for you to test

Microsoft Copilot Chat is Abertay’s supported general AI assistant for students.

AI tools differ in what they can search and retrieve. Some search the web or particular academic collections, but do not assume that an assistant has searched LibrarySearch, Abertay’s subscribed resources or all the literature relevant to your question.

Treat AI suggestions as a starting point. When developing a search:

• Check that suggested terms are relevant and that the search tool supports the proposed operators and symbols.

• Test the search in an appropriate database or search tool, examine the results and adjust your terms.

• Check any suggested sources yourself. A source may be invented, unsuitable or fail to support the claim made about it.

Boolean operators can give you more control over how your terms are combined. Use them when they help with your task; not every search needs a complex search string or a formal search strategy. Where your assessment or research method requires a structured, documented search, AI assistance does not replace those requirements.

See AI for researching a topic for fuller guidance on checking sources and AI-generated answers. The Library’s Search and discovery tools guide explains how to choose suitable search routes.