I’m including John Hattie in the Educational Thinkers’ Hall of Fame because of his reputation for research into positive influences on students’ learning. He was already a well-known academic when he made an international impact with his 2009 book, ‘Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement’.

Visible Learning – 15 years of research
He based this book on the biggest ever collection of evidence-based research into the most important influences on school-aged students’ achievements. He considered many factors. These included the influence of home, school, curricula, teachers and teaching strategies. His findings are relevant to adult education too.

He analysed all the evidence that he had collected and ranked the various factors in order of their ‘effect-sizes’. Some of his variables, such as ‘feedback’ or ‘acceleration’ can mean different things to different people and Hattie explained them more fully in his narrative.

Hattie’s average effect-sizes
He…