The Research

Laureate Professor 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 1,400 meta-analyses comprising more than 93,000 studies involving more than 250 million students around the world.

Hattie’s research is now the world’s largest evidence base on what works best in schools to improve learning.

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? Hattie set about calculating a score or “effect size” for each, according to its bearing on student learning and taking into account such aspects as its cost to implement. The average effect size was 0.4, a marker that represented a year’s growth per year of schooling for a student. Anything above 0.4 would have a greater positive effect on student learning.

The power of the Visible Learning research lies not only in helping educators understand how much impact each factor has on student achievement, but also in understanding impact relative to other factors. Educators who understand which factors have the highest impact on student achievement can begin making strategic decisions based on evidence to maximise their time, energy, and resources.