Students now see two different metrics when they complete a section. The section "Score" and the section "Memory strength".
"Score" is how well the student just did on the section. The score is exactly the same as the score that teachers see on the teacher platform. To get a score of 100%, students need to answer all the questions correctly.
"Memory strength" is a long term measure of how well students know a section. To boost it, students need to repeat the section at just the right times based on the principles of spaced repetition from cognitive science.
Repeating the section will help students store the knowledge in their long term memory so they won't forget it during their exams.
To find out the right time to repeat a section, students simply need to hover over the tooltip next to "Memory strength". Or they can use Smart Learning mode which will let them know when it's a great time to repeat a section and boost their memory strength.
We don't want learners to binge on a section and so students can't max out memory strength in one go - instead they must return and study the section at the right times! If a student fills up their memory strength it means they have practised the section a ton and probably don't need to do it again for a while as they aren't likely to forget it :)