The Evidence on Teaching

Explore the evidence

8 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

group / setting

cost

outcome class

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: low

10/1018/48connected:Feedback and formative assessment Mastery learning (teach → test → r Spaced (distributed) practice

Retrieval 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: low

7/712/48connected:Interleaving (mixing problem types Math-fact fluency and timed practi Retrieval practice (the testing ef

Spaced (distributed) practice · practice · ages 6–18 · method

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: low

12/1236/48connected:Do career and technical education

Ability 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: medium

8/830/48connected:Algebra timing

Acceleration and gifted programs — the label vs the content · grouping · ages 5–18 · structure

Feedback on the task helps modestly; feedback on the person backfires — a stable third of studies reverse. The famous 0.4–0.7 number has no computed source.

mixedconf: highgc: low

18/1812/48connected:Retrieval practice (the testing ef Does teaching music produce musica Placement and mastery diagnosis

Feedback and formative assessment · feedback · ages 5–18 · 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: low

7/718/48connected:Spaced (distributed) practice Science content sequencing

Interleaving (mixing problem types vs blocking) · practice · ages 10–18 · method

Sort by what the software replaces: adaptive drill inside the school day buys +0.05-0.20 SD; a device, a connection or the teacher buys zero to negative; LLM tutors have no usable evidence at all.

mixedconf: mediumgc: low

53/5339/48connected:Placement and mastery diagnosis Mastery learning (teach → test → r Tutoring Class-size reduction

Does educational technology raise learning — CAI, adaptive software, devices, screens, and AI tutors? · edtech · ages 5–18 · structure

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: low

25/2536/48connected:Talent and trainability Can executive function be trained,Should a school buy a social and e Are self-control and grit teachabl

How 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.