The Evidence on Teaching

Explore the evidence

9 of 88 decisions · clear everything

Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
evidencealldrop DA–BA only
evaluatoranyno dev-ledindependent
durabilityanyfollow-up≥1yr≥2yr
what are these? →
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domain
verdict
confidence
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Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
cost
outcome class

Smaller classes buy real K-1 gains that fade on tests yet persist in attainment — at roughly triple tutoring's cost, and diluted to nothing when scaled fast.

mixedconf: highgc: low
7/748/48connected:TutoringDoes educational technology raise Teacher quality

Class-size reduction · class-size · ages 4–18 · structure

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: low
18/1836/48

Do later school start times increase adolescent sleep, and does that raise achievement? · health · ages 11–18 · input

Immersion costs nothing in English and buys a little — a lottery puts English reading 0.13-0.22 SD ahead by grades 5 and 8 — but no lottery has ever measured how much of the second language students actually learn.

moderate supportconf: mediumgc: low
8/824/48

Does dual-language immersion work, and is the gain in the second language or in English? · foreign-language · ages 4–18

Teaching coding teaches coding: the one clean school RCT gives g=0.47-0.68. Which approach you pick barely matters, and almost every effect size rests on an instrument the developers built.

moderate supportconf: mediumgc: low
22/2225/48connected:Does learning to code improve geneTalent and trainability

Does teaching programming actually teach programming — and does the method matter? · computer-science · ages 5–18

Outdoor time prevents myopia from starting (not progressing); screening plus free glasses raises test scores in children who need them. Two claims, both real.

moderate supportconf: mediumgc: low
17/1736/48

Vision — outdoor time against myopia, and screening and correction for achievement · health · ages 4–18 · input

Correcting a real deficiency moves cognition (iron in anaemic children: 0.79 SD); supplementing already-fed children moves nothing (35 RCTs, 19,343 children).

mixedconf: mediumgc: low
20/2018/48connected:Does teaching movement transfer to

Breakfast, school meals, and micronutrients — what feeding children actually buys · health · ages 4–18 · input

Explicit form-focused teaching beats pure exposure, so the archive's negative verdict on L1 grammar does NOT transfer — but the effects are measured on the taught forms, immediately, mostly on adults.

mixedconf: mediumgc: low
11/1118/48connected:Does teaching grammar improve chil

Comprehensible input or explicit grammar teaching — which builds a second language? · foreign-language · ages 4–18

Attainment falls steadily with age of first exposure, but the sharp critical period is contested and an earlier classroom start buys nothing durable: start young for immersion, not for two lessons a week.

mixedconf: mediumgc: medium
14/1424/48

Is there a critical period for learning a second language, and when should a child start? · foreign-language · ages 4–18

School exercise programs don't raise achievement: four of the five largest RCTs are null, and more dose doesn't rescue it. Exercise for health, not for grades.

no effectconf: mediumgc: low
24/2429/48connected:Does teaching movement transfer to

Physical activity as an input — dose, fitness, and school outcomes · health · ages 4–18 · input

The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.