Table 2.
Weight-of-evidence strategies’ effects on changes in attitude. The results presented in Tables 2–4 are based on a 2 (rebuttal vs. advocate silent; between subjects) × 2 (outnumbering 5:1 vs. equal proportion of discussants 3:3; between subjects) × 2 (forewarning vs. no forewarning) × 2 (measurement before vs. after the debate; within subjects) repeated-measures ANOVA (Type II sum of squares). Significant effects are shown in boldface for the significance level of p < 0.05.
| Attitude | Experiment 1 n = 101 |
Experiment 2 n = 390 |
Experiment 3 n = 396 |
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|---|---|---|---|---|---|---|---|---|---|
| Effects | F | p | η2p | F | p | η2p | F | p | η2p |
| Time | 99.16 | <.001 | .506 | 165.42 | <.001 | .302 | 132.11 | <.001 | .254 |
| Rebuttal × Time | 10.01 | .002 | .094 | 24.13 | <.001 | .059 | 50.91 | <.001 | .116 |
| Outnumbering × Time | 0.11 | .737 | .001 | 0.27 | .605 | .001 | 2.10 | .148 | .005 |
| Forewarning × Time | — | — | — | 7.52 | .006 | .019 | 1.11 | .293 | .003 |
| Rebuttal × Outnumbering × Time | 4.68 | .033 | .046 | 0.02 | .883 | <.001 | 2.83 | .093 | .007 |
| Rebuttal × Forewarning × Time | — | — | — | 0.47 | .495 | .001 | 0.16 | .687 | <.001 |
| Outnumbering × Forewarning × Time | — | — | — | 1.40 | .239 | .004 | 0.02 | .886 | <.001 |
| Rebuttal × Outnumbering × Forewarning × Time | — | — | — | 0.54 | .462 | .001 | 3.37 | .067 | .009 |