Table 1's lower segment describes study task participation for relevant groups. The numbers completing all three assessments (98% to 100%) were similar across relevant groups, as were proportions of Low and High LR subjects who watched all four videos (94% to 99%). There were small, but significant, differences among Low or among High LR participants for the average number of videos watched, average minutes spent per video, and number of correct answers to post-video questions. Slightly fewer videos were watched by Low LR subjects in the LRB Group, which could have diminished the impact of videos on their outcomes. However, these differences could not be used as covariates in the following analyses when the outcome evaluations included Controls, as none of those subjects were assigned videos.
