Assessment and Classroom Learning / Inside the Black Box

Narrative review (~250 studies)

K-12 and higher-ed classroom studies.

Contains NO computed meta-analysis. The famous 0.4-0.7 range appears only in the Phi Delta Kappan essay/pamphlet as 'typical effect sizes' with no derivation given anywhere (Bennett 2011).

The advocacy landmark that launched the global formative-assessment movement — whose headline number has no source. The conceptual contribution (five FA strategies) is real; the quantitative claim is 'the educational equivalent of urban legend' (Bennett). The most-cited number in assessment policy has no causal warrant.

N/A (narrative review); underlying quasi-experiments rarely controlled ability composition.

The 0.4-0.7 has NEVER been reproduced: the only computed meta gives 0.20; the developer's own at-scale RCT gives 0.09-0.10.