The purposes of a Knowledge Check are to determine exactly what students know at the time they complete it, and to identify topics students have previously mastered or learned that they haven’t demonstrated retention of. When students demonstrate in a Knowledge Check that they haven’t retained a previously mastered or learned topic, either by selecting I Don’t Know or by answering a related question incorrectly, that topic may move from the Mastered or Learned category to the Remaining category, and be put back in the Learning Path to be learned again.