Search tips

Last changed: 01 February 2024

When searching in a database you can get more relevant results by defining what you are looking for and using keywords wisely. Here are some useful tips.

Finding search terms

When searching for information, the search terms you use make all the difference. They need to be broad enough to cover your research question, yet specific enough to reduce irrelevant hits. Finding information is a process, and we have listed a few tips and tools to help you find the terms to use.

Use both free text and controlled vocabulary

  • Free text searches are typically run in title, abstract, and keywords fields.
  • Many databases provide a thesaurus, a hierarchial list with controlled subject terms. They are a great tool not only for searching from, but also to browse and thereby finding search terms in a hierarchical context. For a systematic search, you should always combine with free text synonyms.
  • By combining your standard search terms with the ones provided in a database thesaurus, you will have a better chance of finding relevant information. 

Find synonyms

Keep in mind that the same phenomenon can have different names in different subject areas.

Consider the hierarchy of your terms

A simple term might capture what you need, and there is no need to add extensions for that term unless you are looking for the extended term only.


  • Urban covers ‘urban city’, ‘urban area’, ‘urban planning’

Consider whether the overarching term is sufficient, or if you need to use the specific terms instead. Searching for both urban and the specific terms yields no additional results in the search. 

Iterative method

Searching for information often requires you to test, adjust, and search again. Start with a few key articles and select relevant terms from the title, abstract, and keywords. Run a test search with these terms. If this captures other highly relevant articles, try to find more terms in them. Repeat as needed.

Tools for finding terms

Here are some tools that can be useful for translating terms:

Combining search terms

When searching in databases, you usually want to be able to control how the search terms are combined with each other. This is often done using AND, OR, and NOT. In most databases, these need to be written in uppercase.

  • AND: All terms must be present. AND is often the default, and if you don't type anything between your search words, the search engines will interpret it as AND.

  • OR: At least one of the terms are present. Use for synonyms or related terms.

  • NOT: Specified terms will be excluded. Note that this may also exclude relevant information, and should therefore be used with caution.


In most databases, parentheses can be used to group terms and to express in what order the database should search the different terms. The parentheses tells the search engine to search the terms within them first, together, and then combine them with the terms outside of the parentheses. An alternative in some databases is to write the different groups of terms in different search boxes.


  • (horse OR pony) AND riding – This search will capture results which contains both ‘horse’ and ‘riding’, or ‘pony and ‘riding’.  


If you would like to search for all various endings of a word, without typing all of them as separate terms, you can use truncation, or stemming. The symbol used for truncation varies in different databases, but it is often an asterisk (*).


  • Farm* yields results for farmer, farmers, farming
  • Sustainab* yields results for sustainable, sustainability, sustainabilities

Keep in mind not to place the asterisk too early, as you risk getting result on terms that are not relevant to your search. In many databases, it is also not possible to use truncation on too short terms.


  • stress* yields results on words like stressing, stressful
  • stre* yields results on the above, but also on terms like streak, street, and stream 

Phrase searching

Phrase searching can be used when searching for search terms consisting of two or more words, such as a specific combination of terms, the name of an organization, a long title, or an author. The search will only retrieve records with the words in exactly the specified order. Many search tools use quotation marks to denote a phrase.


  • "sustainable development goal"
  • "food safety" 

Proximity search

Proximity searching may come in handy when a specific phrase search is to narrow – and a combination of search terms turns out to be too broad. When you perform a proximity search you find terms occurring close to, but not necessary right after, each other.


  • agriculture NEAR/5 challenge – retrieves articles where the two words are found within 5 words from each other, regardless of the order of appearance.

The syntax for proximity searching differs between databases, so make sure to check the help files. 

Search in blocks

For more advanced searches where multiple aspects need to be combined, you can arrange your search in blocks. This is particularly useful in systematic searching.

Search for one group of terms or aspect at the time, using OR. Then combine your groups, search blocks, with AND. Then you make sure that all search blocks yield a big enough result. This also allows you to easily adjust your search string if needed.

The database search history feature can be useful as it provides an overview and the possibility to combine search blocks in an effective way. 


Search one aspect at the time:

  1. (biodiversity OR diversity OR diverseness OR variety)
  2. ("urban area*" OR cities OR city OR town*)
  3. (park* OR "green area*" OR "green space*") 

Combine the search blocks, using AND, either by entering all search terms within parentheses, alternative 1, or by using the search blocks sets number, alternative 2: 

  • Alternative 1: (biodiversity OR diversity OR diverseness OR variety) AND ("urban area*" OR cities OR city OR town*)  AND (park* OR "green area*" OR "green space*") 

  • Alternative 2: #1 AND #2 AND #3