Explore the evidence
14 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
Timed retrieval practice builds arithmetic automaticity — beating identical untimed tutoring head-to-head — and the anti-timed-test harm claims have no causal evidence.
strong supportconf: highgc: lowMath-fact fluency and timed practice (and the anti-timed-test claims) · math · ages 5–12
Minimal-guidance math trailed every rival in the one multi-curriculum RCT; explicit instruction for strugglers is math's most replicated result.
moderate supportconf: highgc: lowExplicit vs reform/constructivist math instruction · math · ages 5–18
Word-problem solving is its own skill: computation fluency doesn't produce it. Teaching problem schemas explicitly does (~0.25–0.45 SD on trained content).
moderate supportconf: highgc: lowWord problems, schema instruction, and the conceptual-vs-procedural question · math · ages 6–14
Neither acceleration mandates nor delay mandates work — readiness-matched placement does. Push everyone and the median falls; hold everyone back and the top falls.
mixedconf: highgc: lowAlgebra timing — acceleration mandates, delay mandates, and readiness-based placement · math · ages 11–18
The textbook matters at the bottom, not the top: avoid the demonstrated losers; mainstream choices now differ by ~0.02 SD.
mixedconf: highgc: lowMath curriculum choice — how much does the textbook matter? · math · ages 5–14
Selective CTE high schools raise male graduation 8-10pp and early-career earnings 17-35% on lottery and cutoff designs; test scores, degrees, and every outcome for girls are flat.
moderate supportconf: mediumgc: lowDo career and technical education tracks help students — and which students? · practical · ages 14–18
Manipulatives help when bland, guided, and aged ~7–11 — a guided-representation effect, not 'hands-on learning.' Rich, toy-like objects hurt transfer.
moderate supportconf: mediumgc: lowManipulatives and concrete-representational-abstract (CRA) sequences · math · ages 5–14
Life-skills courses reliably teach the content and rarely change the conduct; behaviour moves only where instruction sits close in time to the decision, and driver education is worse than nothing.
mixedconf: mediumgc: lowDo life-skills courses — money, cooking, driving, health — change what students actually do? · practical · ages 6–18
Near-zero in primary and almost entirely correlational in secondary. The causal base is three small trials; what the homework IS beats how much of it there is.
mixedconf: mediumgc: mediumHomework — effects by age and by dosage · homework · ages 5–18 · structure
Guided inquiry is positive in 16 of 16 PISA regions and unguided inquiry negative in 18 of 20 — but the programmes built on that finding go to zero at scale: +0.22, then +0.01, then +0.02 on the same test.
mixedconf: mediumgc: lowInquiry-based science teaching vs explicit and textbook science teaching · science · ages 8–18
Two reviews screened ~12,000 records and found one RCT and six quasi-experiments. What evidence exists favours interest (+0.12) over attainment (+0.01), and simulations match real apparatus.
mixedconf: mediumgc: lowLaboratory and practical work in school science · science · ages 5–18
Conceptual-change teaching reliably moves the test and nothing shows it removes the intuition. Corrected for design and publication bias, a taught unit is g≈0.64 and a refutation text g≈0.28.
mixedconf: mediumgc: lowScience misconceptions and conceptual change — can naive intuitions be taught away? · science · ages 6–18
Narrow reasoning routines are teachable and stay taught for seven months. The far-transfer claim failed its one randomised test: science −0.01, English −0.15, maths −0.11.
no effectconf: mediumgc: lowTeaching students to think scientifically — does it transfer? · science · ages 7–18
No trial has ever varied the sequence of science content and measured the result. The one quasi-experimental test of course order found nothing, and depth-over-breadth is a retrospective survey worth 0.08-0.13 SD.
insufficientconf: mediumgc: mediumScience content sequencing — coherence, prerequisites, and course order · science · ages 5–18
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.