John Hattie describes Know Thy Impact

[@TavgaHawrame]

student evaluation improve teachers impact.. this is impressive subject

[@georgelilley6185]

"everything works" is a fundamental claim you make, but when i look at the studies you cite a lot of things don't work, e.g., your best Feedback Study, Kluger & Denisi report OVER 38% of feedback does not work (by the way u report this study as 32% but that's a mistake they report OVER 38%, p. 258). Marzano (2009) also notes this and goes further, "I’ve observed the same phenomenon with virtually every strategy and every innovation I’ve examined. I’ve come to the conclusion that you can expect anywhere from 20% to 40% of the studies in any given area to report negative results." (p. 34)