Effect Size Analysis: Traditional vs. Flipped Classroom

Summary Statistics

Statistical vs. Practical Significance

Statistical: The result is NOT statistically significant (p = 0.052 > 0.05). The study narrowly missed the conventional significance threshold.

Practical: Despite the non-significant p-value, the effect size (d = 0.40) is educationally meaningful and aligns with typical education intervention effects.

Context-Specific Interpretation

Education Benchmark (Hattie, 2009): Average effect across 800+ education meta-analyses = d = 0.40

Your d = 0.40 is exactly at the average for education interventions. This represents a typical, educationally meaningful effect size.

Real-world meaning:

• 5.6-point improvement on test scores
• Could represent crossing a grade boundary (e.g., D+ to C-)
• Similar to other active learning interventions (typical range: d = 0.30-0.60)

Key Insight: The Large Sample Paradox (Inverted)

This study demonstrates the small sample limitation: A potentially meaningful effect (d = 0.40) failed to reach statistical significance due to limited sample size (n=87 total).

The confidence interval tells the story: 95% CI [-0.025, 0.825]

• The interval is WIDE (range = 0.85)
• It barely includes zero (-0.025), explaining the p = 0.052
• True effect could be anywhere from “no difference” to “moderate-large”

What this means:

• Non-significant p-value does NOT mean “no effect”
• The point estimate (d = 0.40) suggests a real, meaningful benefit
• More data needed to reduce uncertainty

Statistical Power Analysis

For d = 0.40 with 80% power at α = 0.05:

• Required: ~100 per group (200 total)
• Current: 42 and 45 per group (87 total)
• Achieved power: Approximately 50-55% (underpowered)

The study had only about 50% chance of detecting this effect. This explains the marginal p-value.

Recommendations

Interpretation for Decision-Making

Don’t dismiss this finding because p = 0.052. The effect size suggests flipped classroom may offer meaningful benefits comparable to other validated teaching methods.

Options:

1. Replicate with larger sample (~100 per group) to confirm
2. Conduct meta-analysis combining this with similar studies
3. Pilot implementation with ongoing assessment
4. Consider costs: If flipped classroom requires minimal additional resources, the potential d = 0.40 benefit may justify adoption

Reporting Recommendation (APA Format)

“Students in the flipped classroom condition (M = 74.1, SD = 13.8) scored higher than those in traditional teaching (M = 68.5, SD = 14.2), though the difference did not reach conventional statistical significance, t(85) = 1.97, p = .052, d = 0.40, 95% CI [-0.03, 0.83]. The moderate effect size (d = 0.40) is consistent with the broader active learning literature (Hattie, 2009) and suggests potential educational benefit, though the wide confidence interval indicates substantial uncertainty. Replication with larger samples is warranted.”

Domain Comparison

Your effect is right in the expected range for flipped classroom interventions.

Bottom Line

Verdict: Educationally meaningful effect that failed to reach statistical significance due to small sample size. The d = 0.40 represents a typical, valuable improvement for education interventions. The marginal p-value (0.052) should not overshadow the substantive effect size.

Action: This is a candidate for further investigation, not dismissal. The point estimate suggests flipped classroom offers benefits comparable to established teaching methods, but the wide confidence interval necessitates replication or meta-analytic synthesis before making definitive conclusions.