Moving beyond our pet theories, cherished convictions and faddish clichés. By Lyndsay Connors.

According to the promo on its cover from the Times educational supplement, Visible Learning "reveals teaching's Holy Grail". This was a risky gambit. Of course, it excites curiosity to know what the Holy Grail of teaching might be. But it risks resistance from readers in a field like education, littered with holy grails. Its author being John Hattie, Professor of Education and Director of the Visible Learning Labs, University of Auckland, New Zealand, my curiosity triumphed. The book reports the outcomes of his 15 year research and synthesis of over 800 meta-analyses relating to the...