Educational research - how can we measure complex systems?
Middle management, in a recent personal development session, was introduced to the research of John Hattie on effective teaching strategies in his publication visible learning . In essence, Mr Hattie advocates that through the meta-analysis of thousands of educational research papers, certain interventions are more effective in the classroom than when compared to others. I have in previous posts linked to his research in support of certain teaching techniques like direct instruction. However recently, my colleague Ximena brought to my attention some admissions around his methodology by Mr Hattie and with further reading of primary literature problems began to emerge. The aspect of Hattie's research that is being brought to the fore by policymakers and prominent educationalists is the effect size. A number greater than 0.4 is a highly effective intervention in the classroom as seen from the above chart. So how did Mr Hattie come up with these effect sizes? Norwegian r