Table 3.
Impact of chemical messages and pictorial warnings
| Effect size for chemical messages (d) | Effect size for pictorial warnings (d)12 | |
| Negative affect | Medium (0.31) | Large (0.54) |
| Thinking about the harms of smoking | Small (0.15) | Small (0.18) |
| Thinking about the message | Small (0.01) | Large (0.61) |
| Perceived likelihood of harm from smoking | Small (0.04) | Small (0.00) |
| Number of conversations about label in the past week | Small (0.15) | Medium (0.26) |
| Quit intentions | Small (0.04) | Small (0.18) |
Cohen’s d of <0.20 is a small effect, 0.20–0.50 is a medium effect and >0.50 is a large effect.64