Explore the evidence
13 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
Systematic phonics beats whole language for word reading — largest in K-1 and for at-risk readers; near-null for comprehension and past grade 3.
strong supportconf: highgc: lowSystematic/explicit phonics vs whole language and balanced literacy · reading · ages 4–9
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
Comprehension is knowledge — but vocabulary teaching moves standardized comprehension only d≈0.10. The big content-knowledge bet (Core Knowledge lottery, 0.24) is real and unreplicated.
moderate supportconf: mediumgc: lowBackground knowledge and vocabulary as drivers of reading comprehension · reading · ages 5–14
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: lowDoes teaching programming actually teach programming — and does the method matter? · computer-science · ages 5–18
Phonemic awareness transfers to reading only with letters attached: speech-only training peaks near 10 hours and moves reading d=0.19; with print, 0.66.
moderate supportconf: mediumgc: lowPhonemic awareness training (and whether it needs letters) · reading · ages 4–7
Guided oral reading works, but the ingredient is volume, not repetition: at equal exposure, re-reading has no edge over wide reading.
moderate supportconf: mediumgc: lowReading fluency — guided repeated oral reading, and whether repetition matters · reading · ages 6–12
A missed day costs little (~0.005 SD); interventions reliably buy days back cheaply, but nobody has shown the recovered days move achievement.
mixedconf: mediumgc: mediumChronic absenteeism — does raising attendance raise achievement? · time · ages 4–18 · input
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
Taking time away hurts measurably; adding it back buys almost nothing. The return per hour is ~0.02-0.03 SD, concave, and near zero in disorderly classrooms.
mixedconf: mediumgc: lowLength of the school day and year, time-on-task, extended time, and summer · time · ages 4–18 · structure
Reading Recovery buys large short-term gains at high cost; the only US long-term estimate is negative. Early 1:1 tutoring works — this model's durability is unproven.
mixedconf: mediumgc: lowReading Recovery and Tier-2 1:1 early-literacy tutoring · reading · ages 5–8
Strategy instruction is a one-time boost, not a trainable skill: six sessions buy what fifty do, and modern at-scale trials are ~null.
mixedconf: mediumgc: lowReading-comprehension strategy instruction (reciprocal teaching, summarizing, questioning) · reading · ages 8–14
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
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.