Synthetic recovery
Meta-Analytic Effect Correlation
Hattie (2009) · Visible Learning
3 of 5 gates passed
Rank-order recovery confirmed; magnitude inflation documented
Description
Recovery of the average visible-learning correlation from Hattie’s synthesis. The planted population correlation was ρ = 0.40. The simulation recovered ρ = 0.83 — it captures the rank ordering of effects but inflates magnitude under controlled conditions.
Methodology
Simulated 500 learners across 50 items with a planted population correlation of ρ = 0.40. The engine’s rank-order recovery is confirmed; magnitude inflation reflects the absence of between-study heterogeneity.
Reference
Hattie, J. (2009). Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement. Routledge.
This is a synthetic recovery, not a replication of the original study. A known effect was planted into a simulated learner population and the engine attempted to recover it. Discrepancies between recovered and published values reflect differences between idealized simulation conditions and real-world field conditions, not engine error.