For each participant, two videos from sessions one through six (pre-intervention) and two videos from sessions 37 to 41
(post-intervention) were selected at random from the pool of videos in those phases. To reduce potential expectancy bias,
mothers were blinded to whether videos were from pre- or post-intervention sessions. Each participant’s mother first
watched the four videos of their child in a random sequence without completing the MSRIQ or GCARS. Mothers where then
shown each video a second time and asked to fill out the MSRIQ and GCARS immediately following each video. Therefore, the
MSRIQ and GCARS were completed four times by each mother (i.e., one MSRIQ and one GCARS rating for each baseline video
and one each per post-intervention video).