Creeping out of the liminal space - what is "collective teacher efficacy"?

Recently, I noticed in John Hattie's most recent visible learning effect sizes, "collective teacher efficacy" took the top spot with an effect size of 1.57 (or explained in other words, 4 years growth in 1 year). 

My first thoughts...someone, please explain! 

Breaking it down, I imagined that collective teacher efficacy is based around the mindsets that teachers have that contribute to their own and their students' success.

After watching this fabulous webinar by Kristin Anderson, I gained an incredible insight into how collective teacher efficacy can be developed in schools. Making relevant connections to Hattie's findings, Anderson explains why it's so important and how schools can move towards making positive  changes. It's about implicitly and explicitly building the personal space of students. I am so excited to look at how I can bring  this into my school! I urge you to watch and be inspired.

Go to Kristin Anderson's webinar