They help to define searches and return only relevant articles in your field. “HIV transmission” intravenous sexual AND methodsīoolean operators can save you time. “HIV transmission” intravenous sexual AND review By adding “AND” before the word we ensure to retrieve only the type of article we are looking for. We also added the word “methods” to retrieve articles relating to methodology. For example, we added the word “review” to our search terms to retrieve only review articles. Search terms are not limited to subject words, you can also use Boolean operators to search for author names or types of articles. HIV transmission (intravenous AND sexual) NOT behavior HIV transmission (intravenous OR sexual) NOT behavior Searching for Articles Using Boolean OperatorsĬorrespondingly, to demonstrate the effect of Boolean operators, we performed a search on PubMed for articles relating to common types of HIV transmission and tabled the number of articles returned for each search: Boolean operator Double quotes: It helps to include an exact phrase in your search.Round brackets: For complex searching when you need your search to be performed in a certain order.This helps to exclude irrelevant articles. NOT: In order to exclude a word from your search results.This is helpful for synonyms and broadens your search results. OR: When you want to search either of the words but not necessarily all of them.AND: In order to combine search words and include all of them in your search.The most common Boolean operators are as follows: Boolean operators can be used alone as well as in combination, depending on how specific your search needs to be.
The “Help” page of the database you are searching will tell you how to use them on that database. Most journal index databases have the Boolean operator function and require them to be capitalized. Boolean Operators (most commonly AND, OR, NOT) are used to narrow or broaden search results.