Explore the evidence
6 of 88 decisions · 4 collapse at your settings · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
verdict
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
- nothing assessed yet
group / setting
- nothing assessed yet
cost
- nothing assessed yet
outcome class
- nothing assessed yet
Testing yourself beats rereading — robust in real classrooms; honest durable size ~0.1–0.3 SD, biggest after delay, thinnest on transfer.
strong supportconf: highgc: lowinsufficient at your settings0/1018/48connected:Feedback and formative assessmentMastery learning (teach → test → rSpaced (distributed) practice
Retrieval practice (the testing effect) · practice · ages 8–18 · method
Spacing beats massing at equal total time — the most robust finding in learning science. Space repetitions at ~10–20% of how long you need to remember.
strong supportconf: highgc: lowinsufficient at your settings1/712/48connected:Interleaving (mixing problem typesMath-fact fluency and timed practiRetrieval practice (the testing ef
Spaced (distributed) practice · practice · ages 6–18 · method
High-dosage tutoring is education's most reliable lever: ~0.29 SD in trials, ~0.2 well-scaled — not Bloom's 2σ. Groups of 3–4 work; 1:1 is unnecessary.
strong supportconf: highgc: low5/1830/48connected:Class-size reductionDoes educational technology raise The parent as instructorSchool spending, charters, and wha
Tutoring — the honest effect, the Bloom 2-sigma myth, and what survives scale · tutoring · ages 5–18 · method
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: lowinsufficient at your settings1/1812/48connected: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: lowinsufficient at your settings0/69/48connected: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.