Explore the evidence
6 of 88 decisions · clear everything
Executive function trains like a task, not like a capacity: gains are real, narrow, and gone at follow-up, EF curricula are null under independent trial, and the latent construct is ~100% heritable.
no effectconf: highgc: lowCan executive function be trained, and does it transfer to learning? · character · ages 4–18
Not at school: the largest randomised trials find nothing on reading, maths or cognition. A small effect on laboratory executive-function tasks is contested, may be real at ~0.2 SD, and is end-of-treatment only.
mixedconf: mediumgc: mediumDoes learning music make children smarter or better at school? · music · ages 4–16
The received wisdom that retention is harmful was two measurement errors, not a finding. Fix them and the achievement effect is zero — but the grade at which you hold a child back decides everything.
mixedconf: mediumgc: lowGrade retention — holding a child back versus promoting, and test-based promotion policies · retention · 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
Coaching buys ~0.25 SD of score and has for 42 years — a fraction of what's advertised — and none of it is ability. The score moves; the construct doesn't.
mixedconf: mediumgc: mediumTest preparation — does coaching raise scores, and does a raised score mean raised ability? · assessment · ages 5–18 · structure
No study of homeschooling has a counterfactual — the famous percentile claims are selection all the way down. The honest answer: nobody knows.
insufficientconf: lowgc: highDoes homeschooling raise achievement and attainment, or does it select the children who would have done well anyway? · homeschool · ages 5–18 · structure
- Algebra timing — acceleration mandates, delay mandates, and readiness-based placement
- Does arts education raise academic achievement?
- Chronic absenteeism — does raising attendance raise achievement?
- Does working-memory or brain training transfer to intelligence and achievement?
- Class-size reduction
- Curriculum choice as a school-level lever
- Deliberate practice and the 10,000-hour rule
- Physical activity as an input — dose, fitness, and school outcomes
- Feedback and formative assessment
- The early home environment — what parents can and cannot causally move
- Homeschool socialisation — the most-asked question, and the least answerable one
- Mastery learning (teach → test → reteach to criterion → advance)
- Math curriculum choice — how much does the textbook matter?
- Does teaching movement transfer to cognition, achievement, or lifelong activity?
- Feedback frequency and mental practice in motor learning
- Practice scheduling for motor skills — varied vs blocked, spaced vs massed
- Should Gardner's multiple intelligences be used as a basis for instruction?
- Breakfast, school meals, and micronutrients — what feeding children actually buys
- Preschool at scale — Head Start, state pre-K, and what universal provision delivers
- Perry Preschool and Abecedarian — what the famous studies actually establish
- Reading-comprehension strategy instruction (reciprocal teaching, summarizing, questioning)
- Reading Recovery and Tier-2 1:1 early-literacy tutoring
- School spending, charters, and what school-level choices actually move outcomes
- School starting age, relative age, and academic redshirting
- Early sport specialization, talent selection, and the relative age effect
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.