John Hattie of the University of Melbourne, Australia, has long researched performance indicators and evaluation in education. His research, Visible Learning, is the culmination of more than 25 years of examining and synthesizing more than 1,600 meta-analyses comprising more than 95,000 studies involving 300 million students around the world.
Hattie wanted to understand which variables were the most important. Although “almost everything we do improves learning,” why not prioritize the ones that will have the greatest effect?