Explore the evidence
27 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
- science5
- writing5
- arts4
- health4
- debunked3
- history civics3
- practice3
- assessment2
- character2
- grouping2
- homeschool2
- instruction style2
- motor skills2
- behavior1
- class size1
- computer science1
- curriculum1
- deliberate practice1
- feedback1
- foreign language1
- homework1
- mastery1
- physical development1
- practical1
- school structure1
- sport1
- talent1
- teachers1
- time1
- transfer1
- tutoring1
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
Grit is conscientiousness renamed and adds 0.4% to grade prediction; self-control genuinely predicts life outcomes but is 60% heritable with zero shared environment, and training moves ratings, not lives.
mixedconf: highgc: medium13/2036/48connected:Should a school buy a social and eDoes teaching a growth mindset raiHow should a school run its classr
Are self-control and grit teachable levers on achievement? · character · ages 4–18
Growth-mindset interventions change beliefs almost everywhere and change achievement almost nowhere: the two independent national-scale trials measured standardized tests and found exactly zero.
mixedconf: highgc: low9/1829/48connected:FadeoutSystematic/explicit phonics vs whoTalent and trainabilityAre self-control and grit teachabl
Does teaching a growth mindset raise achievement? · character · ages 4–18
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: low16/1836/48
Do later school start times increase adolescent sleep, and does that raise achievement? · health · ages 11–18 · input
Yes, on their own terms: lottery-assigned museum and theatre trips move blind-rated analysis of art, plot knowledge and tolerance by 0.08-0.18 SD weeks later, and a film of the same play moves nothing.
moderate supportconf: mediumgc: lowAre museum and theatre trips worth the day out of school? · arts · ages 8–18
Teaching handwriting works and transfers: freeing the hand frees composition, with gains still present at six months — even taught in groups of three.
moderate supportconf: mediumgc: medium8/818/48connected:Does teaching grammar improve chilDoes teaching movement transfer toDoes sentence combining improve wrDoes teaching spelling work, and w+1
Does handwriting and transcription instruction matter, and should young children type instead? · writing · ages 5–12
Sentence combining improves writing where grammar teaching fails — the same meta-analyses score them +0.50 and −0.32.
moderate supportconf: mediumgc: low8/89/48connected:Does teaching grammar improve chilDoes teaching movement transfer toDoes handwriting and transcriptionDoes teaching spelling work, and w
Does sentence combining improve writing? · writing · ages 5–18
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
Formal spelling instruction works (ES 0.54) and more formal beats less formal — explicit wins again, and it transfers beyond spelling itself.
moderate supportconf: mediumgc: low7/79/48connected:Does teaching grammar improve chilDoes sentence combining improve wrSystematic/explicit phonics vs whoExplicit instruction vs discovery/+3
Does teaching spelling work, and what does it transfer to? · writing · ages 5–18
Diagnose what a child already knows: teachers cut 40–50% of curriculum for high-ability children and achievement ROSE. The payoff is skipping, not monitoring.
moderate supportconf: mediumgc: medium10/1625/48connected:Does educational technology raise Feedback and formative assessmentMastery learning (teach → test → r
Placement and mastery diagnosis — deciding what to teach next from evidence of current skill · assessment · ages 5–18 · structure
Content-rich history teaching raises history knowledge (g 0.19-0.46) but not standardized reading in under three years; generic 'historical thinking' has no adequately controlled positive result.
moderate supportconf: mediumgc: lowShould history be built on content knowledge or on generic historical-thinking skills? · history-civics · ages 5–18
Capitalisation and punctuation move when directly taught and directly measured, and don't move when embedded in writing programmes. A teachable subject, not a writing lever.
mixedconf: mediumgc: mediumCan capitalisation, punctuation and usage be taught directly as their own subject? · writing · ages 5–18
Explicit form-focused teaching beats pure exposure, so the archive's negative verdict on L1 grammar does NOT transfer — but the effects are measured on the taught forms, immediately, mostly on adults.
mixedconf: mediumgc: lowComprehensible input or explicit grammar teaching — which builds a second language? · 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: low9/1148/48
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: low18/1936/48
Does civic education produce civic knowledge, and does civic knowledge produce civic behaviour? · history-civics · ages 5–18
The headline effects are a measurement artefact: drama gives d≈0.89 on researcher-made tests and d≈0.29 on standardized ones, and the two randomised trials with standardized outcomes are null.
mixedconf: mediumgc: mediumDoes classroom drama build verbal and literacy skills? · arts · ages 5–16
Document-based instruction reliably improves the sourcing and argument tasks it teaches (g ≈ 0.42) and, in the two best-identified trials, moves neither standardized reading nor history knowledge.
mixedconf: mediumgc: lowDoes document-based source work move history knowledge, reading comprehension, or neither? · history-civics · ages 8–18
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: medium14/1629/48
Homework — effects by age and by dosage · homework · 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: low21/2536/48connected: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
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: low14/1927/48connected:Science content sequencingExplicit instruction vs discovery/Laboratory and practical work in sTeaching students to think scienti
Inquiry-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
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: medium30/3336/48connected: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
Trust the composite; distrust the breakdown. Subtest strengths-and-weaknesses replicate at chance on retest, and most of what people read off a score report is noise.
mixedconf: mediumgc: low18/2124/48
What a standardized achievement score does and does not license · assessment · ages 5–18 · structure
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: medium11/1515/48connected:Background knowledge and vocabularInterleaving (mixing problem typesExplicit instruction vs discovery/Inquiry-based science teaching vs +1
Science content sequencing — coherence, prerequisites, and course order · science · ages 5–18
Teaching grammar does not improve writing at any age tested — and it displaces the things that do.
negativeconf: mediumgc: low11/1227/48connected:Comprehensible input or explicit gDoes sentence combining improve wrDoes teaching spelling work, and wDoes handwriting and transcription+4
Does teaching grammar improve children's writing? · writing · ages 5–18
Nobody has tested it. There is no controlled trial in which art instruction is the input and independently measured art skill is the outcome — the field's core claim is the one it never studied.
insufficientconf: lowgc: medium5/618/48connected:Does arts education raise academicBrain Gym, Whole Brain Teaching, aAre museum and theatre trips worth
Does teaching visual art produce artistic skill? · arts · ages 4–18
Not yet assessed for this question · 47
- 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
- Homeschool socialisation — the most-asked question, and the least answerable one
- 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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