Explore the evidence

9 of 88 decisions · clear everything

Survives the gold standard Independent, durable, rigorous The debunked shelf Cheap wins For parents at home Famous numbers, deflated Where we admit ignorance The terrain

evidenceall drop D A–B A only

evaluatorany no dev-led independent

durabilityany follow-up ≥1yr ≥2yr

what are these? →

Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”

who's delivering

teacher1

group / setting

cost

medium1

outcome class

domain skill1

Timed retrieval practice builds arithmetic automaticity — beating identical untimed tutoring head-to-head — and the anti-timed-test harm claims have no causal evidence.

strong supportconf: highgc: low

7/711/48connected:Does homeschooling raise achieveme Spaced (distributed) practice Word problems, schema instruction,

Math-fact fluency and timed practice (and the anti-timed-test claims) · math · ages 5–12

Minimal-guidance math trailed every rival in the one multi-curriculum RCT; explicit instruction for strugglers is math's most replicated result.

moderate supportconf: highgc: low

10/1021/48connected:Explicit instruction vs discovery/

Explicit vs reform/constructivist math instruction · math · ages 5–18

Word-problem solving is its own skill: computation fluency doesn't produce it. Teaching problem schemas explicitly does (~0.25–0.45 SD on trained content).

moderate supportconf: highgc: low

7/78/48connected:Math-fact fluency and timed practi Worked examples (studying solution

Word problems, schema instruction, and the conceptual-vs-procedural question · math · ages 6–14

Neither acceleration mandates nor delay mandates work — readiness-matched placement does. Push everyone and the median falls; hold everyone back and the top falls.

mixedconf: highgc: low

9/936/48connected:Acceleration and gifted programs School starting age, relative age,

Algebra timing — acceleration mandates, delay mandates, and readiness-based placement · math · ages 11–18

The textbook matters at the bottom, not the top: avoid the demonstrated losers; mainstream choices now differ by ~0.02 SD.

mixedconf: highgc: low

11/1124/48connected:Background knowledge and vocabular School spending, charters, and wha

Math curriculum choice — how much does the textbook matter? · math · ages 5–14

Unallocated money is the worst buy in the database; the same dollars as No-Excuses charters buy +0.3–0.4 SD/yr — and the average charter is a precise null.

mixedconf: highgc: low

8/839/48connected:Tutoring Background knowledge and vocabular Teacher quality Math curriculum choice

School spending, charters, and what school-level choices actually move outcomes · school-structure · ages 4–18 · structure

Brain training improves the trained task and nothing else: far transfer to intelligence or achievement is 0.001 against active controls.

no effectconf: highgc: low

18/1824/48connected:Fadeout Talent and trainability Does learning to code improve gene Can executive function be trained,+1

Does working-memory or brain training transfer to intelligence and achievement? · transfer · ages 4–18 · debunked

Manipulatives help when bland, guided, and aged ~7–11 — a guided-representation effect, not 'hands-on learning.' Rich, toy-like objects hurt transfer.

moderate supportconf: mediumgc: low

3/36/48

Manipulatives and concrete-representational-abstract (CRA) sequences · math · ages 5–14

Coding instruction teaches coding (d≈0.68) and not thinking: against active controls far transfer is g=0.15, two validated-instrument RCTs found d≈0.00, and a 46-school maths trial found −0.16 to −0.21.

no effectconf: mediumgc: low

21/2118/48connected:Does working-memory or brain train Does teaching programming actually Fadeout

Does learning to code improve general thinking? · transfer · ages 5–16

The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.