Feedback has a medium overall effect on student learning (d = 0.48 after outlier removal) with substantial heterogeneity¶

Claim · All claims
Evidence · 2 studies · 2 quant-synthesis r3 · q3 · i2 medium
Currency · newest study 2020 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i2 The random-effects integration of all study effects yields a weighted average effect size of d = 0.55 (95% CI 0.48–0.62), reduced to d = 0.48 after excluding 3.5% extreme values. → Wisniewski B 2020 q3 i? Effect sizes are highly heterogeneous (I2 = 86.47% before outlier removal; 83.40% after), indicating feedback is not a single consistent treatment. → Wisniewski B 2020 (2)

Evidence¶

Wisniewski B 2020¶

Wisniewski B, Zierer K and Hattie J (2020) The Power of Feedback Revisited: A Meta-Analysis of Educational Feedback Research. Front. Psychol. 10:3087. https://doi.org/10.3389/fpsyg.2019.03087

q3 · i2 · quant-synthesis · r3

Random-effects meta-analysis integrating 994 effect sizes from 435 studies (about 61,000 subjects) identified from 32 existing meta-analyses. The pooled d = 0.55 (CI 0.48–0.62) fell to "a reduction of the average weighted effect size to 0.48" after excluding 35 extreme effect sizes.

"The integration of all study effects with the random-effects model leads to a weighted average effect size of d = 0.55. 17% of the effects were negative. The confidence interval ranges from 0.48 to 0.62."

Wisniewski B 2020 (2)¶

Wisniewski B, Zierer K and Hattie J (2020) The Power of Feedback Revisited: A Meta-Analysis of Educational Feedback Research. Front. Psychol. 10:3087. https://doi.org/10.3389/fpsyg.2019.03087

q3 · i? · quant-synthesis · r3

Q-test of homogeneity across all 994 effect sizes shows "The probability of homogenous effects is <0.001" with I2 = 86.47%, i.e., considerable heterogeneity; after outlier removal I2 remained 83.40%.

"The probability of homogenous effects is <0.001 with Q = 7,339 (df = 993) and I2 = 86.47%."

Discussion¶

Related Claims¶

• Feedback improves learning by a medium amount on average, but its effect varies widely with the information it carries, and a substantial share of feedback effects are negative — the general claim this finding bears on, with the studies behind it
• Feedback in CALL has a significant moderate positive effect on student language learning outcomes (RE g = 0.56) across 21 studies — related
• Variation in meta-analytic effect sizes stems from synthesists' methodological choices (inclusion criteria, data extraction, formulas, outlier handling) and from study quality — related
• Feedback Addressing Task Improves Learning — related
• During feedback provision, both content-specific support (g = 0.48) and generic support (g = 0.55) positively affect peer-feedback processes and outcomes, with no significant difference between them — related
• Meta-analysis yields a lower feedback effect (d = 0.48) than the Visible Learning meta-synthesis (d = 0.79), with three synthesized values overestimated — related
• Effect sizes across included studies show high heterogeneity (all I² above 75%) — related
• Effect sizes across studies show substantial heterogeneity, with wide prediction intervals spanning large negative to large positive true effects — related