The Evidence Pyramid is often used to illustrate the development of evidence. At the base of the pyramid is animal research and laboratory studies - this is where ideas are first developed. As you progress up the pyramid the amount of information available decreases in volume, but increases in relevance to the clinical setting.
http://libraryguides.unh.edu/health-literacy. Adaptation of the Evidence Pyramid Diagram
developed by the Medical Research Library of Brooklyn, SUNY Downstate Medical Center
