What is a 'grain' ?

What is a "grain" ? A key concept or element to be taught and that can be explained in a few seconds of user experience: a definition, a date, an image, a biography, etc.

Each story and content contains grains. Each test is associated with one or multiple "grains" which makes our engine generate revisons in the next lessons. The grain's content will be shown in the "Starter" of next lessons when a user made a previous mistake. Our engine automatically generates auto-evaluation tests to learn and memorize the grains.

How Did We Do?