The play skills intervention was embedded within daily center time. During centers, the teachers set up specific activities
and the children individually rotated through centers to work on goals embedded in each activity. Children spent 5 min in
each center before rotating to the next. Therefore, all intervention sessions were also 5-min long. For each participant the
same toy set was used during every intervention session so that play was only taught with one of the two toy sets. This
allowed for generalization across toys to be assessed with the second toy set in the return to baseline. For Ashley, only the
house set and for Vince and Colt only the amusement park set was used during intervention. Intervention was implemented
individually with each participant daily. However, data were only collected two to three days per week during intervention