# John Hattie Back to [[Reverse Flynn Effect and EdTech]] **Role:** Education researcher; author of Visible Learning - He wrote *Visible Learning* (2009) and *Visible Learning: The Sequel* (2023, Horvath's ref 11). - These books synthesize hundreds of meta-analyses. - The **"hinge point"** of about d = 0.40 is the average effect of an intervention. - ⚠️ Affiliation from memory: University of Melbourne (emeritus). - **Relevance:** Horvath's re-centering subtracts 0.42 from each EdTech effect, which drives the negative numbers. Critics call the benchmark unrealistic (see [[People/Elizabeth Tipton]]).