I really want to understand this and I hope you can help me. Matt Townsley’s blog post and a recent direct marketing email from Carnegie Learning have got me thinking.
I’ve had an opportunity to read and share John Hattie’s research on Visible Learning in middle level endorsement classes and I do believe, overall, he’s onto something. There are hundreds of strategies or programs teachers can implement to raise student achievement. Some have greater impact than others.
Hattie’s research has taught me to look for the game changers–any strategy that has an effect size of 0.40 or greater is worth implementing. I’m not a statistician but I’m using that effect size to help me navigate through the maze of educational products being touted.
This is where I become confused. The research abstract states, “The estimated effect is statistically significant for high schools…” And the conclusions state, “The effect size of approximately 0.20 is educationally meaningful” (page 27).
I’m perplexed. The RAND research says this is statistically significant and educationally meaningful. Hattie’s yard stick would say it has low impact.
What are your thoughts? Can you clarify my befuddlement?