If you are aware of the theoretical work of John Hattie, you may have heard about Effect Size. Effect Size if a simple measure for quantifying the difference between two sets of data on a common scale. As part of our partnership focus on Visible Learning I have examined this year’s student NAPLAN data with John Hattie’s effect size tool. Results show that 20% of Riverton PS students have achieved more than two years’ growth in at least one area of NAPLAN in 2017.