Explore the evidence
10 of 88 decisions · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
domain
- math6
- reading6
- early childhood5
- health4
- debunked3
- homeschool3
- practice3
- grouping2
- instruction style2
- motor skills2
- practical2
- arts1
- behavior1
- class size1
- curriculum1
- deliberate practice1
- feedback1
- foreign language1
- history civics1
- mastery1
- physical development1
- retention1
- school structure1
- sport1
- talent1
- teachers1
- time1
- transfer1
- tutoring1
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
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: low18/1836/48
Do later school start times increase adolescent sleep, and does that raise achievement? · health · ages 11–18 · input
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
Immersion costs nothing in English and buys a little — a lottery puts English reading 0.13-0.22 SD ahead by grades 5 and 8 — but no lottery has ever measured how much of the second language students actually learn.
moderate supportconf: mediumgc: low8/824/48
Does dual-language immersion work, and is the gain in the second language or in English? · foreign-language · ages 4–18
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: low11/1148/48
Do life-skills courses — money, cooking, driving, health — change what students actually do? · practical · ages 6–18
Civics teaching buys civic knowledge (d = 0.49) that fades to the control mean in two years and moves neither attitudes nor validated turnout; what moves voting is school quality and noncognitive skill.
mixedconf: mediumgc: low19/1936/48
Does civic education produce civic knowledge, and does civic knowledge produce civic behaviour? · history-civics · ages 5–18
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: low19/1936/48
Grade retention — holding a child back versus promoting, and test-based promotion policies · retention · ages 5–18 · structure
Classroom order is causally worth a great deal — one disruptive peer costs classmates 3% of adult earnings — yet no branded behaviour programme reliably delivers it and exclusion makes things worse.
mixedconf: mediumgc: low25/2536/48connected:Talent and trainabilityCan executive function be trained,Should a school buy a social and eAre self-control and grit teachabl
How should a school run its classrooms and its discipline system? · behavior · ages 4–18 · structure
What parents are asked to DO is the whole effect: tutoring a skill d≈1.15, listening to reading 0.51, reading aloud ~0.18 — same parent, same child. All deflate under better designs.
mixedconf: mediumgc: medium33/3336/48connected:Homeschool socialisationDoes homeschooling raise achievemeThe early home environmentTutoring
The parent as instructor — what survives when the person teaching is the person who raised the child · homeschool · ages 4–18 · method
No study of homeschooling has a counterfactual — the famous percentile claims are selection all the way down. The honest answer: nobody knows.
insufficientconf: lowgc: high23/2336/48connected:Homeschool socialisationThe parent as instructorSystematic/explicit phonics vs whoMath-fact fluency and timed practi
Does homeschooling raise achievement and attainment, or does it select the children who would have done well anyway? · homeschool · ages 5–18 · structure
Homeschoolers get plenty of social contact but measurably fewer, closer peer ties; whether that helps or harms has never been causally tested.
insufficientconf: lowgc: highHomeschool socialisation — the most-asked question, and the least answerable one · homeschool · ages 6–18 · structure
Not yet assessed for this question · 46
- Acceleration and gifted programs — the label vs the content
- Algebra timing — acceleration mandates, delay mandates, and readiness-based placement
- Does arts education raise academic achievement?
- Chronic absenteeism — does raising attendance raise achievement?
- Background knowledge and vocabulary as drivers of reading comprehension
- 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
- Explicit instruction vs discovery/inquiry — how much guidance?
- Explicit vs reform/constructivist math instruction
- Fadeout — why early gains disappear, and what actually persists
- Feedback and formative assessment
- Ability grouping and tracking — four practices, four verdicts
- The early home environment — what parents can and cannot causally move
- Interleaving (mixing problem types vs blocking)
- Does matching instruction to a child's "learning style" improve learning?
- Manipulatives and concrete-representational-abstract (CRA) sequences
- Mastery learning (teach → test → reteach to criterion → advance)
- Math curriculum choice — how much does the textbook matter?
- Math-fact fluency and timed practice (and the anti-timed-test claims)
- Brain Gym, Whole Brain Teaching, and the smaller classroom brain fads
- 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
- Phonemic awareness training (and whether it needs letters)
- Systematic/explicit phonics vs whole language and balanced literacy
- 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 fluency — guided repeated oral reading, and whether repetition matters
- Reading Recovery and Tier-2 1:1 early-literacy tutoring
- Retrieval practice (the testing effect)
- School spending, charters, and what school-level choices actually move outcomes
- School starting age, relative age, and academic redshirting
- Spaced (distributed) practice
- Talent and trainability — what is heritable, and what that does not license
- Teacher quality — selection over credentials and workshops
- Tutoring — the honest effect, the Bloom 2-sigma myth, and what survives scale
- Vision — outdoor time against myopia, and screening and correction for achievement
- Word problems, schema instruction, and the conceptual-vs-procedural question
- Worked examples (studying solutions vs solving problems)
- Early sport specialization, talent selection, and the relative age effect
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