Explore the evidence
4 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
- writing6
- early childhood5
- science5
- arts4
- character4
- health4
- assessment3
- debunked3
- foreign language3
- history civics3
- homeschool3
- practice3
- grouping2
- instruction style2
- motor skills2
- music2
- practical2
- time2
- transfer2
- behavior1
- class size1
- computer science1
- curriculum1
- deliberate practice1
- edtech1
- feedback1
- homework1
- mastery1
- physical development1
- retention1
- school structure1
- sport1
- talent1
- teachers1
- tutoring1
verdict
confidence
layer
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
- nothing assessed yet
group / setting
- nothing assessed yet
cost
- nothing assessed yet
outcome class
- nothing assessed yet
Teacher quality is the largest within-school lever — 1 SD of teacher ≈ 0.10–0.15 SD/yr, worth more than ten fewer students — and credentials predict none of it. Select; don't workshop.
strong supportconf: highgc: lowTeacher quality — selection over credentials and workshops · teachers · ages 4–18 · structure
Smaller classes buy real K-1 gains that fade on tests yet persist in attainment — at roughly triple tutoring's cost, and diluted to nothing when scaled fast.
mixedconf: highgc: lowClass-size reduction · class-size · ages 4–18 · structure
The famous faded-feedback demo doesn't survive meta-analysis; mental practice is real at half the advertised size and never substitutes for physical practice.
mixedconf: highgc: lowFeedback frequency and mental practice in motor learning · motor-skills · ages 4–18
Varied practice looks worse today and better at retention — in the lab. Applied settings shrink the edge to zero, and it reverses in under-18s.
mixedconf: highgc: lowPractice scheduling for motor skills — varied vs blocked, spaced vs massed · motor-skills · ages 4–18
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.