Explore the evidence
3 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
- health4
- assessment3
- debunked3
- homeschool3
- practice3
- arts2
- foreign language2
- grouping2
- instruction style2
- motor skills2
- time2
- behavior1
- class size1
- curriculum1
- deliberate practice1
- feedback1
- history civics1
- homework1
- mastery1
- physical development1
- practical1
- retention1
- school structure1
- science1
- sport1
- talent1
- teachers1
- transfer1
- tutoring1
verdict
confidence
layer
Your situation · from the applicability layer — absence means “not yet assessed,” never “doesn’t apply”
who's delivering
group / setting
outcome class
Immersion costs nothing in English and buys a little — a lottery puts English reading 0.13-0.22 SD ahead by grades 5 and 8 — but no lottery has ever measured how much of the second language students actually learn.
moderate supportconf: mediumgc: low8/824/48
Does dual-language immersion work, and is the gain in the second language or in English? · foreign-language · ages 4–18
Attainment falls steadily with age of first exposure, but the sharp critical period is contested and an earlier classroom start buys nothing durable: start young for immersion, not for two lessons a week.
mixedconf: mediumgc: medium14/1424/48
Is there a critical period for learning a second language, and when should a child start? · foreign-language · ages 4–18
Taking time away hurts measurably; adding it back buys almost nothing. The return per hour is ~0.02-0.03 SD, concave, and near zero in disorderly classrooms.
mixedconf: mediumgc: low23/2338/48
Length of the school day and year, time-on-task, extended time, and summer · time · ages 4–18 · structure
Not yet assessed for this question · 1
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.