TABLE 3.
Journal club presentation scores for the comparison and intervention groupsa
| Test | Comparison group mean (SD) | Intervention group mean (SD) | Welch's t test | Cohen's d (effect size) |
|---|---|---|---|---|
| All items | 3.63 (0.46) | 3.97 (0.60) | t = −2.19, df = 41.18, P = 0.034 | 0.64 (medium) |
| LOCs | 4.06 (0.44) | 4.29 (0.47) | t = −1.80, df = 44.78, P = 0.078 | 0.52 (medium) |
| HOCs | 3.27 (0.56) | 3.69 (0.73) | t = −2.25, df = 41.02, P = 0.030 | 0.65 (medium) |
| Introduction | 3.99 (0.66) | 3.94 (0.87) | t = 0.22, df = 40.95, P = 0.827 | 0.06 (minimal) |
| Hypotheses | 3.48 (0.77) | 3.95 (0.81) | t = −2.02, df = 45.11, P = 0.050 | 0.58 (medium) |
| Methods | 2.03 (0.58) | 2.75 (0.88) | t = −3031, df = 37.74, P = 0.002 | 0.96 (large) |
| Analyses | 3.89 (0.70) | 4.22 (0.80) | t = −1.52, df = 44.05, P = 0.135 | 0.44 (small) |
| Significance | 3.85 (0.64) | 4.21 (0.77) | t = −1.73, df = 42.74, P = 0.090 | 0.50 (medium) |
| Narrative synthesis | 3.53 (0.80) | 4.11 (0.93) | t = −2.30, df = 43.81, P = 0.026 | 0.67 (medium) |
a
Welch's t test and Cohen's d both assumed unequal variance in the samples. Cohen (48) recommends effect size values of 0.2, 0.5, and 0.8 be considered “small,” “medium,” and “large,” respectively, for Cohen's d.