How the mastery indicator works
The four mastery levels, the four factors behind them, why the number can fall on its own, and how it gates the posttest.
Last updated: July 26, 2026
Four levels
Every practice you have attempted carries a mastery badge showing how strong your grip on it currently is:
- Needs Work, below 50%
- Developing, 50% to 69%
- Proficient, 70% to 84%
- Mastered, 85% and above
The four factors behind the number
It is not simply your last session's accuracy. Four things feed into it:
- Recent accuracy. Latest attempts weigh more than older ones.
- Practice frequency. More attempts build confidence in the number.
- Consistency. Stable scores rank higher than erratic ones.
- Time decay. Skills fade when they are not practised.
Why it can drop without you doing anything
Because of that fourth factor. If a practice goes untouched for a while, its percentage declines on its own. This is deliberate and not a penalty: language skills genuinely fade without repetition, so the number tries to be honest about where you are today rather than where you were three months ago.
Redoing a practice whose percentage has slipped usually lifts the number faster than starting a new one, because you improve recent accuracy and frequency at the same time.
How it gates the posttest
A part's posttest unlocks once every practice in that part reaches Mastered. The mastery badge is not decoration: it decides when you are ready to move on to the next assessment.