Mastery is recalculated incrementally as students answer questions and complete assessments (quizzes and diagnostic exams). With each additional answer, the system learns more about the students’ current level of mastery.
Mastery is broken into three levels that correspond to low, medium, and high performance. At any given time, the system uses the learner’s performance history to calculate the probability that the learner is at Level 1, 2, or 3. We can never know precisely and absolutely what the learner’s actual performance level is, so the system calculates the probability that a learner is in each of the three levels. For example, a low-performing student (based on their question answering patterns) is most likely at Level 1. There is a small chance that the learner is actually capable of performing at Level 2 and an even smaller chance that they are capable of performing at Level 3. Given these probabilities, the learner is “awarded” Level 1. As his or her performance improves, the probability that the learner’s underlying ability is low decreases and the probability that it is medium or high increases. Once there is a greater probability that the learner is a medium performer, he or she is awarded Level 2.