Concept mastery
Concept mastery is how well you actually know one single idea, measured and tracked over time instead of guessed. It rises when you get that idea right and slips back down when you leave it alone, so your study plan can always see what still needs work.
In more detail
Mastery is the honest version of "I think I know this." A score per idea tells you the truth: this one is solid, that one is shaky, this other one you got right once a week ago and have probably half-forgotten by now. That last part matters. Your brain forgets things on a curve, so a concept you nailed on Monday is not the same strength by Friday.
It works by watching how you do, concept by concept. Get a question right and that idea's score goes up. Miss it, and the score drops. And even when you do nothing, the score is allowed to fade with time, the way real memory fades. So the weak and the going-stale ideas float to the top, and those are the ones worth drilling next.
The common mistake is studying what feels easy. Re-reading the chapter you already get feels productive, but it does almost nothing. Mastery flips that. It points you straight at the ideas you keep missing or are about to forget, which is exactly where your time pays off.
Example
Priya is studying for a biology exam with 40 concepts in her course. Most are green, but "the Krebs cycle" keeps coming up red because she misses it on every quiz. Her practice keeps handing her Krebs questions until that score finally climbs, instead of wasting her on the stuff she already knows.
How StudyPDF does this
Bo scores every concept in your uploaded material and lets the weak ones fade over time, so it always knows which ideas you keep getting wrong. Then it drills those in your next quiz or flashcards instead of repeating what you already have down.
See also
Common questions
Why does my mastery go down when I haven't studied?
Because memory fades, and your score is built to match that. An idea you got right two weeks ago is not as fresh in your head now, so letting the score drift down keeps it honest. It is a reminder to review before you forget completely, not a punishment.
Is concept mastery the same as my grade or quiz score?
No. A quiz score is one snapshot of one sitting. Mastery is per idea and it stretches over time, so it can tell you that you understand 35 of your 40 concepts but keep tripping on 5 specific ones. That detail is what tells you exactly what to drill, which a single grade can't.
Put it to work on your own course
Upload your lectures and ask Bo. Cited answers, plus flashcards, exams, and more built from your material.