Attendance is counted.
Practice isn't.
Observation costs make systems optimise for what is easy to report, not what matters.
01 / The transfer problem
The training happens.
The teaching doesn't change.
Education systems invest heavily in teacher development and count attendance because classroom practice is expensive to observe.
Across four years of longitudinal evidence, we found that roughly one teacher in eight showed observable, sustained change in classroom practice.
12.5%Observed training-to-practice transfer
Validated findingAbout 1 in every 8 teachers
showed observable, sustained classroom change after conventional professional development.
350+ teachers · 8 countries · 4 yearsAttendance is counted.
Coaching works.
It doesn't scale.
Sustained observation and feedback change practice, but human cadence remains scarce.
The stakes are
demographic.
Millions of teachers must be developed—not replaced—as demand keeps growing.