Explore the evidence
3 of 88 decisions · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
verdict
confidence
layer
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
- nothing assessed yet
group / setting
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cost
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outcome class
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The 10,000-hour rule is dead: practice explains ~14% of performance variance, is itself heritable, and identical twins 20,000 hours apart didn't differ. Necessary, insufficient.
mixedconf: highgc: mediumDeliberate practice and the 10,000-hour rule · deliberate-practice · ages 6–18 · method
Feedback on the task helps modestly; feedback on the person backfires — a stable third of studies reverse. The famous 0.4–0.7 number has no computed source.
mixedconf: highgc: low18/1812/48connected:Retrieval practice (the testing efDoes teaching music produce musicaPlacement and mastery diagnosis
Feedback and formative assessment · feedback · ages 5–18 · method
Mastery learning moves tests of what it taught (~0.25) and barely moves independent measures (~0.05) — and time-to-mastery gaps widen, converting ability differences into time.
mixedconf: highgc: low6/69/48connected:Does educational technology raise Retrieval practice (the testing efPlacement and mastery diagnosis
Mastery learning (teach → test → reteach to criterion → advance) · mastery · ages 6–18 · method
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.