Explore the evidence
20 of 88 decisions · 4 collapse at your settings · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
domain
- math5
- reading5
- arts4
- early childhood4
- health4
- science4
- history civics3
- practice3
- writing3
- foreign language2
- grouping2
- homeschool2
- instruction style2
- motor skills2
- time2
- assessment1
- character1
- class size1
- computer science1
- curriculum1
- debunked1
- feedback1
- homework1
- music1
- physical development1
- practical1
- retention1
- school structure1
- sport1
- teachers1
survival prior
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
Testing yourself beats rereading — robust in real classrooms; honest durable size ~0.1–0.3 SD, biggest after delay, thinnest on transfer.
strong supportconf: highgc: low2/1018/48connected:Feedback and formative assessmentMastery learning (teach → test → rSpaced (distributed) practice
Retrieval practice (the testing effect) · practice · ages 8–18 · method
Spacing beats massing at equal total time — the most robust finding in learning science. Space repetitions at ~10–20% of how long you need to remember.
strong supportconf: highgc: lowinsufficient at your settings1/712/48connected:Interleaving (mixing problem typesMath-fact fluency and timed practiRetrieval practice (the testing ef
Spaced (distributed) practice · practice · ages 6–18 · method
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: medium9/2036/48connected: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
Teaching movement teaches movement: the skills improve, but transfer to cognition, achievement, or lifelong activity is near zero in the best trials.
no effectconf: highgc: medium2/710/48connected:Does arts education raise academicPhysical activity as an inputDoes teaching grammar improve chilDoes handwriting and transcription+5
Does teaching movement transfer to cognition, achievement, or lifelong activity? · physical-development · ages 4–18
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
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
Unassisted discovery loses to explicit teaching; well-scaffolded guided discovery beats both. The operative variable is guidance, not ideology.
moderate supportconf: mediumgc: lowinsufficient at your settings1/1315/48connected:Worked examples (studying solutionExplicit vs reform/constructivist Science content sequencingInquiry-based science teaching vs +1
Explicit instruction vs discovery/inquiry — how much guidance? · instruction-style · ages 4–18 · method
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
Novices learn faster studying solutions than solving problems — then the effect reverses with expertise. Use worked examples early; fade them.
moderate supportconf: mediumgc: lowinsufficient at your settingsWorked examples (studying solutions vs solving problems) · instruction-style · ages 10–18 · method
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: low12/1936/48
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
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
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: medium5/1629/48
Homework — effects by age and by dosage · homework · ages 5–18 · structure
One systematic review kept 39 studies from 11,771 records; another found 1 RCT among 53. 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
No. The two randomised programmes that tested it — 42 Houston schools and five EEF trials across 400 English schools — return nulls on reading and maths; only writing, the outcome nearest the treatment, moves.
no effectconf: mediumgc: low2/49/48connected:Does teaching movement transfer toDoes teaching visual art produce aAre museum and theatre trips worthDoes classroom drama build verbal
Does arts education raise academic achievement? · arts · ages 5–14
School exercise programs don't raise achievement: four of the five largest RCTs are null, and more dose doesn't rescue it. Exercise for health, not for grades.
no effectconf: mediumgc: lowPhysical activity as an input — dose, fitness, and school outcomes · health · ages 4–18 · input
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: mediuminsufficient at your settings1/1515/48connected: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: low4/1227/48connected: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
No study of homeschooling has a counterfactual — the famous percentile claims are selection all the way down. The honest answer: nobody knows.
insufficientconf: lowgc: high3/2336/48connected: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
Not yet assessed for this question · 42
- Acceleration and gifted programs — the label vs the content
- Algebra timing — acceleration mandates, delay mandates, and readiness-based placement
- Are museum and theatre trips worth the day out of school?
- Does teaching visual art produce artistic skill?
- Chronic absenteeism — does raising attendance raise achievement?
- Background knowledge and vocabulary as drivers of reading comprehension
- Class-size reduction
- Comprehensible input or explicit grammar teaching — which builds a second language?
- Curriculum choice as a school-level lever
- Explicit vs reform/constructivist math instruction
- Feedback and formative assessment
- Grade retention — holding a child back versus promoting, and test-based promotion policies
- 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
- Length of the school day and year, time-on-task, extended time, and summer
- Interleaving (mixing problem types vs blocking)
- Does dual-language immersion work, and is the gain in the second language or in English?
- Manipulatives and concrete-representational-abstract (CRA) sequences
- Math curriculum choice — how much does the textbook matter?
- 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)
- Placement and mastery diagnosis — deciding what to teach next from evidence of current skill
- 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
- School spending, charters, and what school-level choices actually move outcomes
- School starting age, relative age, and academic redshirting
- Inquiry-based science teaching vs explicit and textbook science teaching
- Science misconceptions and conceptual change — can naive intuitions be taught away?
- Does sentence combining improve writing?
- Do later school start times increase adolescent sleep, and does that raise achievement?
- Teacher quality — selection over credentials and workshops
- Vision — outdoor time against myopia, and screening and correction for achievement
- Word problems, schema instruction, and the conceptual-vs-procedural question
- Does strategy instruction (SRSD, the writing process) improve writing?
- Early sport specialization, talent selection, and the relative age effect
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