2.3. Experimental design and procedure
The study was completed in a 13-day period. In order to control for the effects of the children travelling and acclimating to
the treatment environment, no treatment was provided on days 1–7. On these days, the child and his/her parents were
instructed to interact with their children in their apartments as they usually did at home. On days 1 and 7 each child
participated in baseline passive interaction probes (PIPs 1 and 2), and on day 13 a final passive interaction probe (PIP 3) was
administered, with SRP provided on days 8–12 for children assigned to the experimental group.