Explore the evidence
11 of 88 decisions · clear everything
- math6
- reading6
- writing6
- early childhood5
- science5
- arts4
- character4
- health4
- assessment3
- debunked3
- foreign language3
- history civics3
- homeschool3
- practice3
- grouping2
- instruction style2
- motor skills2
- music2
- practical2
- time2
- transfer2
- behavior1
- class size1
- computer science1
- curriculum1
- deliberate practice1
- edtech1
- feedback1
- homework1
- mastery1
- physical development1
- retention1
- school structure1
- sport1
- talent1
- teachers1
- tutoring1
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: lowAbility 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: mediumAcceleration and gifted programs — the label vs the content · grouping · ages 5–18 · structure
Brain training improves the trained task and nothing else: far transfer to intelligence or achievement is 0.001 against active controls.
no effectconf: highgc: lowDoes working-memory or brain training transfer to intelligence and achievement? · transfer · ages 4–18 · debunked
Matching instruction to 'learning styles' does nothing: real matching experiments return d=.04. The correlational literature IS the myth.
debunkedconf: highgc: lowDoes matching instruction to a child's "learning style" improve learning? · debunked · ages 4–18 · debunked
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: lowDo 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: lowVision — 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: lowBreakfast, school meals, and micronutrients — what feeding children actually buys · health · ages 4–18 · input
Coding instruction teaches coding (d≈0.68) and not thinking: against active controls far transfer is g=0.15, two validated-instrument RCTs found d≈0.00, and a 46-school maths trial found −0.16 to −0.21.
no effectconf: mediumgc: lowDoes learning to code improve general thinking? · transfer · ages 5–16
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: lowPhysical activity as an input — dose, fitness, and school outcomes · health · ages 4–18 · input
Never operationalised well enough to test: no MI-based trial meets even a loose evidential bar. Four decades in, a valid evaluation is still impossible.
insufficientconf: mediumgc: mediumShould Gardner's multiple intelligences be used as a basis for instruction? · debunked · ages 4–18 · debunked
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: lowBrain Gym, Whole Brain Teaching, and the smaller classroom brain fads · debunked · ages 4–18 · debunked
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