John Hattie: Visible learning: A synthesis of over 800 meta-analyses relating to achievement

This book by John Hattie – Professor of Education at the University of Auckland – is the culmination of more than a decade of research during which he and his team have set out to summarise and synthesise the empirical research on the effects of various educational influences and interventions on student achievement. Probably due to the huge scope of this project – comprising 800 meta-analyses, more than 50,000 smaller studies and more than 80 million pupils – this study has been widely acclaimed. According to a review in the Times Educational Supplement, Hattie’s work ‘‘reveals teaching’s Holy Grail’’. Hattie starts from the observation that in education ‘‘everything seems to work’’, as educational interventions of almost any kind seem to have a positive effect on student achievement. He then proposes to move beyond ‘‘everything goes’’, towards the development of a barometer of ‘‘what works best’’. To this end he applies the tools of meta-analysis to a huge body of empirical research and calculates effect sizes (denoted d) for 138 influences in the following domains: student, home, school, teacher, curricula and teaching approaches. Hattie neatly presents the effect sizes in a graphical barometer and convincingly argues that only effect sizes higher than 0.4 are in the so-called zone of desired effects (in other words, are worth the effort). Prior to presenting the barometers and effect size rankings, Hattie develops his visible learning story, which is summarised in the following quote: ‘‘Visible teaching and learning occurs when learning is the explicit goal, when it is appropriately challenging, when the teacher and student both seek to ascertain whether and to what degree the challenging goal is attained, when there is deliberate practice aimed at attaining mastery of the goal, when there is feedback given and sought, and when there are active, passionate and engaging people participating in the act of learning’’ (p. 22). The visible learning story is illustrated using the example of outdoor training. An instructor teaching rock-climbing will have