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Universiteitsbibliotheek – LibGuides

Master ISS literature search: Search strategy and techniques

elements of your search query

Once you have written down your (re)search question, the next step is to split up your search query in the main elements (you can use your inclusion criteria for that).

Does the use of social networking sites influence cannabis use in adolescence?

Wordt cannabisgebruik in de adolescentie beïnvloed door het gebruik van social-network-sites?

  • WHO is the focus (age, gender, ethnic group, socioeconomic status etc.)?
  • WHAT is the intervention or the idea that is tested?
  • HOW does the WHAT affect the WHO?

example of the elements of a search question: adolescents; cannabis use; social network sites

In the next step you go and find search terms for the different elements.
See also the visualisation of the search query.

Generating search terms

Thinking up the right search terms is one of the major parts of your search strategy.

Go looking for corresponding terms for each part of your search question. Don't forget:

  • ​synonyms (house / dwelling)
  • broader terms (university / higher education)
  • narrower terms (children / toddlers)
  • related terms (training / coaching)
  • antonyms (terms with opposite meanings, such as parent/child or poverty/wealth
  • persons and organisations of importance to your subject
  • terms indicating space and time (for instance eras, centuries, names of places, countries)
  • avoid bias in your search terms, it might colour the outcome of your search

And also think of the different word forms:

  • singular/plural
  • verb conjugations
  • nouns/adjectives
  • different spelling (labor / labour or organisation / organization)
  • abbreviations
  • translations into languages which are relevant to your subject and discipline

Correct your search terms along the way. If you do so from the very start, you will soon see which (new) terms produce the right results, and which terms don't. Repeat this method as long as it takes.

You don't have to reinvent the wheel. Use resources:

  • words from an exploratory search from, for instance, Wikipedia or handbooks
  • words from earlier found sources, for instance words from the title or abstract or keywords given by the author
  • dictionaries
  • thesauri (overviews of selected words or concepts and their mutual relations within a particular field of interest or discipline, often included in large, subject specific databases)


Mindmapping can be a good and fun way to come up with search terms.

A mind map is a diagram made up of concepts, texts, relationships and/or pictures, which are arranged in the form of a tree structure around a central theme, for example (a part of) your search query.

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Search techniques

If you use more than one search term in your search, most search engines will look for documents in which all entered terms occur. Would you like to combine search terms in another way? In that case, you need to use so-called operators. This search method is also called a Boolean search (after George Boole).

The operators most frequently used:

  • AND: both terms must occur. Example: fashion AND France
  • OR: at least one of the terms must occur. Example: fashion OR trend OR hype
  • NOT (or sometimes AND NOT): the term must not occur. Example: fashion NOT clothes
  • "... ...": exact phrase, terms must occur together and in this exact order. Example: "French revolution"
  • * . By putting an asterisk behind the 'trunk' of a word, you search by all possible endings. Example: govern* searches for government, governments, governed, governance, governmental etc
  • Masking/Wild cards: for example a question mark (?) or hashtag (#) may be used to replace an unknown character. Example: labo?r searches both labor and labour; or : wom#n will return results with both woman and women

You can combine operators, much like in mathematical equations. ‘AND’ takes priority unless you use brackets to group concepts: (youth OR adolescent* OR "young adults") AND (bully* OR "peer harassment").

Please take note: operators and wildcards may differ among search engines.

Other techniques you can use:

  • Using keywords generated by the authors or by the makers of a search engine
  • Using thesauruses: (subject related) overviews showing the relation between professional terms
  • Field specific search: indicate that your terms must occur in a particular part of the publication (title, summary, name of the author). Use the 'advanced search' option.
  • Using filters and 'limits': limit your set of results by excluding publications having certain features (for instance filter on language or publication year)

Visualisation search query

visualisatie zoekvraag

Search query:
(adolescent* OR youth) AND (cannabis OR "soft drugs" OR weed OR hashish) AND ("social network sites" OR "social media" OR Facebook OR TikTok)

Search methods

Snowball method: You search on the basis of a suitable publication you have found earlier. For example other publications by the same author, or you go searching for other sources in the reading list of a relevant publication (authors make use of the work of others as a source for their own work, these sources will be mentioned in the reading list of the new publication). This way of searching for references goes back in time to older publications.

Citation searching: see if the article you found has been cited, and if so, have a look at this new article. If this article is also relevant you can see if this article has also been cited, and so on. Use a citation database, like Web of ScienceScopus or search Google Scholar. This search method goes forward in time to newer articles. Please take into account that a recent article may have no citations yet or only just a few.

Catalogue method: Searching with search terms of your own choosing in a search engine that makes literature in a certain collection/collection searchable. For example in WorldCat.

Systematic method: you search on the basis of (combined) search terms in search engines which make literature in a certain discipline (or all disciplines) searchable (regardless of availability) with the intention of finding as much literature as possible on that subject. You may expand (adding search terms you have found) or limit (cancelling search terms or filter on year of publication). You can use several search techniques in the systematic method. ​

Too few results: what to do?

If you do not get enough results, you could:

  • Check your spelling
  • Use less specialist terms
  • Broaden your search by adding alternatives for your search terms in an OR relationship (for instance segregation OR discrimination)
  • Broaden your search by including word varieties: either in an OR relation (for instance: segregation OR segregated) or by truncating your search terms, if allowed by the search engine (for instance: segregat*);
  • Broaden your search by leaving out an aspect/variable
  • Adjust/accentuate your search terms by using the provided keywords and/or thesaurus of a specific search engine/database 
  • Use other search engines and databases

Too many results: What to do?

If you get too many results to view/use you could: 

  • Search more specifically by using more specific search terms
  • Add an extra aspect to your search (with AND)
  • Limit your search to certain years of publication
  • Change the sorting order: sort by relevance but also try year of publication or, if possible, the number of citations
  • Change to a different (subject related) database that better fits your topic