Explore the evidence
4 of 88 decisions · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
survival prior
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
Later bells buy adolescents 40+ measured minutes of sleep — the best-identified positive effect in the archive; the achievement payoff is real but far smaller.
strong supportconf: mediumgc: low18/1836/48
Do later school start times increase adolescent sleep, and does that raise achievement? · health · ages 11–18 · input
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
Perry and Abecedarian: n=123 and n=111, IQ gains gone by adolescence, attainment effects real but multiplicity-fragile. Too thin to carry the policy built on them.
mixedconf: mediumgc: lowPerry Preschool and Abecedarian — what the famous studies actually establish · early-childhood · ages 4–5 · structure
Brain Gym, Fast ForWord, coloured overlays, the Mozart effect: tested and failed, or never evidence-based at all. Mozart works exactly as well as any other music.
debunkedconf: mediumgc: low11/1120/48connected:Does teaching visual art produce aDoes matching instruction to a chiDoes working-memory or brain trainDoes learning music make children
Brain Gym, Whole Brain Teaching, and the smaller classroom brain fads · debunked · ages 4–18 · debunked
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.