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Homepage / Systematic Literature Review – Identifying your search terms and constructing your search strings

Systematic Literature Review – Identifying your search terms and constructing your search strings


books open on a desk

Our previous posts on the systematic review have looked at getting started and selecting your sources. In this post we will look at the next fundamental stage:

  • Identifying your search terms and constructing your search strings

Identifying your search terms

Having decided which sources you need to search, the next step in the systematic literature review process is to identify your search terms or keywords:

  • These may be individual words such as customer, or phrases like “customer research management”. Note: if phrases are not inserted inside double quotation marks, each word will be searched for individually rather than as a phrase, e.g., customer AND service AND management instead of “customer service management”.
  • Your search terms should consist of not just the words which are included in your research question, but also synonyms (e.g. customer OR consumer), spelling variants, and any relevant concepts.
  • Spelling variants such as organization and organisation can be dealt with by using the wildcard symbol (‘?’) in place of a single letter. For example, a search for ‘organi?ation’ will look for both spellings of the word. Note: not all sources accept the wildcard symbol. Check the search tips of your resource for guidance.
  • Use the truncation symbol (‘*’) at the end of a whole or partial word to search for variant word endings. For example, strateg* will find strategy, strategies, strategic etc. Note: not all sources accept the truncation symbol. Check the search tips of your resource for guidance.

When choosing your keywords, remember that the aim is to identify all relevant literature without making the search so broad that you retrieve lots of irrelevant material.  For example, the synonyms for customer in the example below have been combined into a search string using the word OR:

(consumer OR customer OR client OR user)

Note that words such as individual or subject have not been included as these words are homographs and would produce a lot of irrelevant material. Homographs are words that are spelled the same but have more than one meaning. You should also only use ‘sensible synonyms’. For example, in gender studies you would not search using terms such as ‘gentleman’ or ‘lady’. These terms are unlikely to be used by the scholars in your field.

Constructing your search strings

Once you have chosen your keywords and phrases, they can be combined into search strings. Some examples of search strings are given below:

String 1 (“supply chain*” OR “supply network*” OR “demand chain*” OR “demand network*” OR “value chain*” OR “value network*”) 

String 2 (“lead time compression” OR “lead time reduction” OR “cycle time compression” OR “cycle time reduction” OR “dwell time compression” OR “dwell time reduction”)

String 3 (agil* OR “quick response” OR speed*)

Note that each search string only contains synonyms or related terms.

Now that you have created your search strings, you are ready to construct your search strategies.

Other blog posts you may find useful

Contact us

Because of the complexity of this process, we recommend that before embarking on a systematic literature review you speak with your Librarian who will be happy to provide guidance.

Feature image from Pixabay

Mandy Smith

Written By: Mandy Smith

Mandy has worked for Cranfield Library Service since 2004 and is a Research Support Librarian supporting researchers and research students at Cranfield Defence and Security and the School of Management. She teaches a range of study skills as well as helping researchers use the resources they need to find information. She provides advice and support on REF and funder compliance, open access publishing and other research-related topics.

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