Once you have thought about your keywords and alternative keywords, it is time to think about how to combine them to form your search strategy. Boolean operators instruct the database how your terms should interact with one another. 

Boolean Operators

• OR can be used to combine your keywords and alternative terms. For example "Social Media OR Twitter". When using OR we are informing the database to bring articles continuing either of those terms as they are both relevant so we don't mind which appears in our article. 
• AND can be used to combine two or more concepts. For example "Social Media AND Anxiety". When using AND we are informing the database that we need both of the terms in our article in order for it to be relevant.
• NOT can be used to exclude items by eleminating a concept. For example diabetes NOT type 1.

Be careful and use NOT strategically. It can unintentionally exclude relevant articles if the unwanted term appears alongside useful content. 

Don't forget the more ORs you use the broader your search becomes, the more ANDs you use the narrower your search becomes. 

Double quotation marks can be used to allow for phrase searching. This means that if you have two or more words that belong together as a phrase the database will search for that exact phrase rather than words separately.  For example "Social Media"

Truncation can be used when there are multiple possible word endings. Truncation as a technique is used to expand your search and capture multiple word endings with a single root term.

Example Nurs* will find Nurse, Nurses and Nursing. 

Tips:

• The most common truncation symbol is the asterisk * , but some databases may use different symbols. It is always good to check the help section of the database you are searching.
• Avoid truncating too early in a word (e.g., nut*  could retrieve nutrition, but also nuts, nutmeg), which may lead to irrelevant results.
• Start with a full keyword and only truncate when you feel confident the root will yield relevant variations. If unsure, run a test search and scan the first page of results to check how relevant the results are.

Proximity searching allows you to find two or more keywords that appear within a certain number of words from each other in a document. This technique is especially useful when you're looking for concepts that are closely related but not necessarily expressed as exact phrases. 

Example

A search like exercise NEAR/5 "mental health"  will retrieve results where exercise and mental health appear within five words of each other—capturing variations like exercise improves mental health or mental health benefits of regular exercise

Different databases/platforms use distinct syntax for proximity searching and this can vary from database to database.