Explore the evidence
6 of 88 decisions · clear everything
Survives the gold standardIndependent, durable, rigorousThe debunked shelfCheap winsFor parents at homeFamous numbers, deflatedWhere we admit ignoranceThe terrain
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
group / setting
cost
outcome class
Group within classes or across grades by subject: modest, nearly free wins. Whole-school streaming does nothing, and early between-school tracking harms the bottom.
moderate supportconf: highgc: lowAbility grouping and tracking — four practices, four verdicts · grouping · ages 5–18 · structure
Accelerate ready kids: they keep pace with older classmates, bank a year, and show no social-emotional harm at 50. The gifted label itself does nothing; the content does.
moderate supportconf: highgc: mediumAcceleration and gifted programs — the label vs the content · grouping · ages 5–18 · structure
Unassisted discovery loses to explicit teaching; well-scaffolded guided discovery beats both. The operative variable is guidance, not ideology.
moderate supportconf: mediumgc: low13/1315/48connected: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
Mixing problem types helps where confusion is the enemy — discriminating similar categories, mixed math practice — and is useless or worse for facts and prose.
moderate supportconf: mediumgc: lowInterleaving (mixing problem types vs blocking) · practice · ages 10–18 · method
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: medium16/1625/48connected: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
Novices learn faster studying solutions than solving problems — then the effect reverses with expertise. Use worked examples early; fade them.
moderate supportconf: mediumgc: lowWorked examples (studying solutions vs solving problems) · instruction-style · ages 10–18 · method
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