Many of the high effects in the 2009 book e.g., student feedback, linking prior and subsequent learning, going from known to unknown are from the early 1970’s. Are we running the risk of just putting numbers to old ideas?

Research is re – search; perhaps you are right it is ‘searching again’. The book Visible Learning is a literature review. From that John Hattie aimed to extrapolate a story in the hopes of forming a contribution. The interpretations of these successful ideas from the 1970’s is currently still not shared by all of our colleagues.