Literature Review: Searching the literature

"For whatever kind of literature review you undertake, demonstrating that you have thoroughly searched for the evidence included in your review ultimately enhances the credibility of your review findings and conclusions."

(Booth, A., Papaioannou, D. & Sutton, A. 2012, Systematic approaches to a successful literature review, p. 70)

Ways to improve your approach to searching

You can improve your search results by spending some time developing your search strategy:

• Start by looking closely at your research question
• Identify the concepts contained in the research question.
• List keywords which authors would use to describe your topic concepts.
• Don't just use one word for a concept, consider whether there are any synonyms, plurals, acronyms or alternative spellings that can be used.
• Check to see if your database allows for thesaurus searching, i.e. MeSH in PubMed
• Document the search process by keeping a research log
• Try one of the worksheets below to help you explore your research question

Learn from your initial search results!

• Locate relevant references in databases and check what keywords and subject headings have been used to describe them and add any terms that you think are relevant to your search strategy.
• Examine the references in relevant articles to identify more articles for your literature review.
• Do a Cited Reference Search of a significant article to find out who has used that article in their own research.

Use the databases listed below to do a cited reference search:
Web of Science 
Click on the Cited Reference Search tab to identify your source article to see who cites it.
Google Scholar  
Click on the "Cited by" link under the article citation.
Scopus
When viewing your source article,  and citing references are listed on the right side of the screen.

By thinking carefully about how you run your search strategy you can make your search more effective. Here are some tips to help you keep on top of the searching process.

General tips

Document the research process. Keep a research log, which documents where you searched, and what has or has NOT been found. Use the log to keep track of how you've searched and save time by avoiding repetitive searches.

Simplify the search process by searching for each concept individually within a database and then use the search history function to combine them into your overall search.

Most if not all, databases will allow you to create a personal account. You can use this account to save searches, create collections of references and set up alters based on your searches to help you keep informed of new research in your area of research.

Search tips

Boolean Operators

You can use Boolean Operators AND, OR and NOT to improve your searches. Use AND to narrow your search results, OR to broaden and NOT to exclude chosen terms. Check out this short tutorial on using Boolean Operators

Truncation Searching

Truncation searching allows you to retrieve references containing variations on a search term. When using a truncation search, type the first few letters (stem) of the keyword followed by an asterisk (*). The search results will include all potential endings of that stem. For example interact* = interact, interacting, interaction, and interactivity. Check out this short tutorial for more information.

Wildcard Searching

Wildcard operators act as a substitute for a character in a word.  Use this when trying to allow for to account for spelling variations, for example behavio?r = behaviour and behavior.

Phrase Searching

When searching for a phrase such as heart attack, you can improve your search results by placing quotations marks around the phrase i.e. "heart attack". This will force the database to search for those words in that particular order. See this quick tutorial for more information.

Proximity Searching

Proximity operators increase the relevancy of your free text search results by allowing you to search for words that are near each other in the record. For Example patient adj3 anxiety will retrieve records where patient and anxiety appear within 3 words of each other in any order.

Field Searching

Field searching allows you to search within a specific field, such as author or title. For example, If you already know the author of a specific article, searching by their name in the author field will pull more relevant records than a keyword search. It will ensure all results are articles written by the author and not articles about that author or just with that author’s name mentioned anywhere in the record.

Thesaurus Searching

Many databases have thesauri which standardise the words or phrases used to represent concepts. This means you don't need to try and figure out all the ways different authors could refer to the same concept. Examples of thesauri include MeSH in PubMed or CINAHL Headings in CINAHlL. While you shouldn't use thesaurus terms on their own they are very helpful in improving your search strategy. Check out this short video on using MeSH to improve your search.

Limits

Many databases allow you to limit your search to a specific type of article (peer reviewed or refereed for example), articles published within a certain time frame,or specific languages. Using limits will help you to exclude references that you don't need to see.