Using a database
The aim of using a database is primarily to search for materials to be used in the literature review. Various databases are available as mentioned in Step 2: Literature review (Tab 2). However, do seek clarification from your library department to check for the databases that your institution has access to!
Note:
Here, we are showing pictorial guides for Pubmed’s interface but the exact steps and user interface might vary across different database.
You might also be required to register an account for the databases in order to save your searches. Once you have accessed the website of the database, follow the 5-step guide below to search for literature!
Navigate to the “Advanced Search” tool for the database that you are using.21
Using “Advanced Search” will enable us to formulate specific queries that allow the database to help us search for relevant articles based on our criteria.
2. Build your query using Boolean operators.22
Identify keywords that you would like to include from your research question, taking into consideration the ‘PICO’ of your research. The databases will use these words to filter out articles which contain these words based on the Boolean operators that you used. The 3 Boolean operators are:
AND (to filter for articles that contain the combination of keywords where each keyword must be present, this gives you a “stricter” and “narrower” search and typically produces fewer search results)
OR ( to filter for articles that contain the combination of keywords where either of the keywords is present, this gives you a “broader” search and typically produces more search results)
NOT ( to exclude articles containing the particular keyword)
3. Narrow down your search results
Once your query is ready, the database will begin searching for relevant articles. Typically, 2 things can happen: you can either have too many results or too few results. Revising the keywords and Boolean operators that you used previously will change the number of search results accordingly.
Note: Do take time in experimenting with different keywords and Boolean operator combinations so that you can produce a balanced query that yields appropriate search results.
Next, you can refine the search results further by filtering the type of articles, publication dates, journals or other additional search filters available in the database. For example, you might only want to include articles starting from a particular year onwards or particular types of articles like meta-analyses or randomized control trials. This is where your inclusion and exclusion criteria come into play.
4. Selecting literature that is relevant
Once you have sufficient search results, go through them and select the ones that are suitable for your research project. A quick way to do this is to read the “Abstract” as it can provide an overview of the paper.
5. Saving the articles
Saving the articles makes it easier for you to refer back to them whenever needed.