Why did Khan Academy build a new mastery system?

We're removing Missions in June 2020. See here for more information.

Over the years, we’ve experimented with different ways for teachers and students to move through learning at their own pace, starting with Missions five years ago. While we love Missions (and know that many teachers do, too!), we identified several important issues that needed to be fixed.

• Missions are only available for math and not for other subjects
• Missions lack important transparency in terms of understanding what is being tested for and when
• Missions only summarize mastery for a full course instead of summarizing mastery in more accessible, unit-sized chunks
• In addition, we had made it hard for teachers to use Khan for both self-paced learning (e.g. Missions) and for teacher-directed practice to focus on specific skills (e.g. Assignments).

Because our missions code base is aging and these issues required significant structural changes, we needed to develop a new system. Our aim was to create a new system that kept what has always been great about Missions and self-paced learning but allowed for even more exciting functionality that is important to teachers and students.

Mastery and Missions: What's the same?

• Both help students master skills for an entire course (e.g. 3rd-grade math, Geometry).
• Students work at their own pace and level on just the right skills, getting instant feedback and help along the way.
• We celebrate “leveling up” on skills to support motivation and engagement!

Mastery and Missions: What's new and improved?

• We now have instructional content—videos and articles—alongside practice, quizzes, and unit tests throughout the self-paced mastery experience.  
• Students complete exercises, quizzes, and unit tests to earn mastery points.
• Students level up from not practiced to familiar to proficient to mastered, giving a more descriptive idea of where they are in the mastery process
• Mastery can be earned in non-math courses!
• Mastery Challenges! Mastery Challenges in Course Mastery have been improved based on feedback we received from learners and teachers. For instance, we heard from Missions students that they were frustrated that un-practiced skills were being tested in Mastery Challenges in Missions. Mastery Challenges in Course Mastery will only test skills where students have reached the Familiar level or higher. For more information about how Mastery Challenges work, see here.

Note: While the Course Challenge can help learners achieve Course Mastery, the Course Challenge can't be assigned.