Referring to an Evidence Pyramid during the article selection process can help you remember how the domain of the question being asked impacts article selection."Evidence Pyramid" by Dartmouth Biomedical Libraries is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Synthesized research sources appraise the quality of studies and often make recommendations for practice. These could be systematic reviews, meta-analyses, or critically-appraised topics (evidence syntheses).
Primary research databases are used to find original studies. Evidence is not always available via filtered resources. It is possible to use specific search strategies to achieve the highest possible level of evidence.