OttoLearn recognizes that learners will forget things over time. To account for this, the system will automatically calculate a small decrease in each learner's mastery level on a weekly basis, for Concepts they haven't engaged with.

Each learner's rate of forgetting on a Concept is based on how proficiently they executed that Concept's associated Activities.

For example, if a learner is at level 4 mastery on a Concept, and hasn't engaged recently, the system will automatically reduce this level (very gradually) to account for forgetting. Eventually, if the learner never exercises that Concept's Activities, they will drop below level 1.

OttoLearn will project into the future to determine when a learner may drop below their mastery goal due to forgetting, and uses that information to determine which Concepts they need to exercise in each Mastery Moment.