Explore the evidence
2 of 88 decisions · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
domain
verdict
layer
survival prior
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
cost
outcome class
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: low18/1830/48connected: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 received wisdom that retention is harmful was two measurement errors, not a finding. Fix them and the achievement effect is zero — but the grade at which you hold a child back decides everything.
mixedconf: mediumgc: low19/1936/48
Grade retention — holding a child back versus promoting, and test-based promotion policies · retention · ages 5–18 · structure
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.