Extended Data Table 6.

Comparison between the first RCT and online experiments

Comparison of the first RCT and online experiments (pooled across three experiments) in their primary inclusion criteria, key dependent measures, sample characteristics (including the percentage of men, the average and s.d. of participant age, the percentage of participants who were white (excluding Hispanic or Latino), and the percentage of participants who received the influenza shot in either of two recent influenza seasons), and statistics about the estimated effects of adding ownership language and a video-based information intervention to a reminder (including the 95% confidence interval, the absolute value of Cohen’s d or h, and η_p² of each estimated effect). The extent to which a participant wanted the vaccine was only measured in the online experiment conducted in April 2021; for participants in this experiment, the outcome measure was the average of their responses to the two questions listed above. The methods for calculating Cohen’s h and η_p² are described in ‘Methods of investigating intentions versus actual uptake’ in Methods. The values used to calculate η_p² came from the OLS regressions reported in Supplementary Tables 5, 39. Supplementary Information section 4 provides a discussion about this table.