Most clinical encounters lead to a need for information. The first step in EBM is to translate the need for information into a question that can be answered by clinical research. 

There are "foreground" questions and "background" questions.

Background questions:

• look for general knowledge  
• contain a who, what, where, when, or why 
• contain a verb
• look at an aspect of health care, such as treatment, disorder, or test

Foreground questions:

• look for specific information to make treatment decisions
• sometimes called "PICO" questions

Questions might investigate: prevention, cost-effectiveness, quality of life, clinical findings, prognosis, aetiology, or therapy, among others. The question asked determines the types of evidence searched.