Explore the evidence
8 of 88 decisions · clear everything
- 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
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: lowRetrieval 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: lowSpaced (distributed) practice · practice · ages 6–18 · method
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: lowSchool spending, charters, and what school-level choices actually move outcomes · school-structure · ages 4–18 · structure
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
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
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: lowDoes civic education produce civic knowledge, and does civic knowledge produce civic behaviour? · history-civics · ages 5–18
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
Classroom order is causally worth a great deal — one disruptive peer costs classmates 3% of adult earnings — yet no branded behaviour programme reliably delivers it and exclusion makes things worse.
mixedconf: mediumgc: lowHow should a school run its classrooms and its discipline system? · behavior · ages 4–18 · structure
The URL is the state — any view you build here is a permalink you can hand to someone mid-argument.