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Search Tips

Build Your Search Strategy: Combine

Once you have decided on your search terms and how to get the most out of them, the next stage is to combine the different elements of your search.


Use OR, AND, or NOT to join up your concepts. These connectors usually need to be typed in capital letters.

OR – widens your search, as any of the terms will be present in each result.
Use OR to include different synonyms for your concept.

neonates OR premature babies OR premature infants"

This will give you results that include neonates, OR “premature babies”, OR “premature infants”.

OR diagram

AND – narrows your search, as all terms must be present in each result.
Use AND to combine different concepts.

noise AND growth

This will only give you results that include BOTH noise AND growth.

AND diagram

NOTexcludes articles on the concept.
NOT narrows a search as it leaves out records with the specified terms.

noise NOT traffic

This will give you results that include noise BUT will NOT include any results that also include traffic.

NOT diagram
  • Take care using NOT. Here you may exclude some relevant articles that refer to foot traffic through the ward, for example. If you really need to use this, try excluding the term only in the article title.


You can use brackets (parentheses) to group these AND/OR/NOT combinations. If you put a series of terms in brackets, it is effectively a search within a search and works well when you have a group of synonyms which you want to combine using OR, and then want to combine the result with an AND or a NOT search:

Premature AND (babies OR infants)

So in our example, the database will search for articles including the word premature plus either of the two words babies or infants, thus finding articles referring to both premature babies and premature infants. Articles referring to both babies and infants will also be included.

The way you put your search together will depend on the database you use. There are two main database formats: single line search and multi-line search. The way that searches are performed are very similar, but the way they are laid out is slightly different.

Single line search is where you include all the elements of your search in one line.

Scopus is an example of a database where you can use single line search:

Multi-line search is where each element of your search is on its own line. These are combined using either buttons or drop-down lists between lines to select AND, OR or NOT.

Medline is an example of a database where you can use multi-line search:

Multi-line search

Many databases have options to use either single line search or multi-line search. Multi-line search is often called ‘Advanced Search’.

For specific instructions for the database(s) you want to use, check out our guides or make an appointment with a Reference Librarian