Leveling down instead of up.

Hi Brian,

When you answer a question incorrectly, the mastery system generally interprets that as you needing more practice with that certain skill. Research suggests that skills are learned best when they're practiced repeatedly over several days - so it may take a little wile to level back up. This helps to build your mastery of the skill, as you have to keep thinking about it over a several days. 

Hope this helps! Let me know if you have any further questions

I agree