I recently started building Orin, an AI-powered tutoring company. We wanted take the long shot of AI in education: actually building a tutor for every student.

Today, I want to focus on pedagogy - the art of teaching.

Teaching is constrained by human labor. America has a finite number of teachers—~3.7 million of them—and 15 times as many students, making the average class size 16-23 students per class.

In every country, the number of students exceed the number of teachers.

And while class sizes continue to rise and teachers continue to burn out, the research about the best strategy is clear:

On average, students that engage in one-on-one tutoring perform two standard deviations above their peers.

In fact, this is so well known it even has a name: Bloom’s Two Sigma Problem.

Personalized one-on-one instruction is the undisputed best way to help a student improve. Full stop.

But what makes personalized instruction so good? What can it do that nothing else can?

Let’s find out.