and welcome to Course Mastery.

So back in 1984, famous education researcher

Benjamin Bloom published the famous two-sigma study

where he showed that a student who works

in a mastery learning framework with a tutor,

one-on-one can operate two standard deviations better.

So the student who is operating in the 50th percentile

can operate well into the 90th percentile,

95th, 96th percentile.

You fast forward to today, there have been

over 200 studies that have backed up his claims.

On top of that, you as an educator,

know that your students enter your class

at all different levels.

You also know that differentiation has always been

considered a best practice in education.

The hard part, however, is how do you do that

with 25, 30, 35 kids in the classroom?

All of us at Khan Academy, we firmly believe

that if we have to pick between an amazing teacher

and an amazing technology, we'd pick you every time,

the amazing teacher.

Luckily, we don't have to make that trade-off,

and so we're think about how can we empower you,

an amazing teacher, with as powerful technology as possible?

And that's what Course Mastery is.

It's a way for you to set mastery goals

for your students, and these goals are fairly large goals,

so that they'd be appropriate for over a term

or over a school year, and you set it once

and then you can feel confident that over the rest

of the year or the rest of the term,

your students have things to work on

the are appropriate for them.

They'll be able to learn at their own time and pace,

master concepts at their own time and pace,

consistent with Benjamin Bloom's work,

and remediate their gaps as necessary.

And multiple studies have shown that when students

on Khan Academy are able to engage in mastery learning,

learn at their own time and pace,

for even 30 minutes or more per week.

So say 45 minutes a week, or one class period a week,

they're able to accelerate their learning

as measured by standardized benchmark exams

by 20 or 30%.