There are two steps you can take to plan your research before actually going to a database that will
State your research idea as a clinical question, which should be specific and answerable:
example: How effective is the use of mouth guards in reducing mild traumatic brain injury incidence in high school athletes?
Check that your question is indeed a "clinical question" by checking to see that it contains three or four specific variables known as PICO:
here is the same clinical question in PICO format:
|P||"high school athletes" AND "traumatic brain injury"|
You will notice that the Population box above has two variables with an all-caps AND connecting them. This is a Boolean command phrase, and will tell the database that both terms are required.
Charting your question as a PICO gives you pieces of the search phrase you need to search on a database. All you need to do now is combine the pieces correctly, using Boolean commands AND, OR, and NOT
There are several worksheets available directed at planning your search. Here is one example and a guide for thinking through the PICO process.
There are several levels of evidence, all related to the types of research and publications. Many evidence based resources incorporate evidence that ranges from the very highest level to the very basic level.