The Evidence on Teaching

Explore the evidence

8 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? →
sortconfidencerobustfragileA–Z
domain
verdict
confidence
layer
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
cost
outcome class

Teacher quality is the largest within-school lever — 1 SD of teacher ≈ 0.10–0.15 SD/yr, worth more than ten fewer students — and credentials predict none of it. Select; don't workshop.

strong supportconf: highgc: low
11/1136/48connected:School spending, charters, and whaClass-size reduction

Teacher quality — selection over credentials and workshops · teachers · ages 4–18 · structure

Group within classes or across grades by subject: modest, nearly free wins. Whole-school streaming does nothing, and early between-school tracking harms the bottom.

moderate supportconf: highgc: low
12/1236/48connected:Do career and technical education

Ability grouping and tracking — four practices, four verdicts · grouping · ages 5–18 · structure

Accelerate ready kids: they keep pace with older classmates, bank a year, and show no social-emotional harm at 50. The gifted label itself does nothing; the content does.

moderate supportconf: highgc: medium
8/830/48connected:Algebra timing

Acceleration and gifted programs — the label vs the content · grouping · ages 5–18 · structure

Teaching movement teaches movement: the skills improve, but transfer to cognition, achievement, or lifelong activity is near zero in the best trials.

no effectconf: highgc: medium
7/710/48connected:Does arts education raise academicPhysical activity as an inputDoes teaching grammar improve chilDoes handwriting and transcription+5

Does teaching movement transfer to cognition, achievement, or lifelong activity? · physical-development · ages 4–18

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

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

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

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