The following factors were considered when selecting toys for use in this study: (a) participants’ age, (b) participants’
exposure to specific toys prior to the study, (c) appropriateness of toys for the classroom, and (d) participants’
preference for specific toys. First, teachers were asked to make a list of toys that the school currently did not own that
would be appropriate in the classroom. New toys (i.e., toys not available to the participants prior to the study) were
identified to reduce the potential confound of an uncontrolled history of reinforcement involving any specific toy
previously available in the classroom. Second, age appropriateness of toys was determined by observing the toy play of
same age typically developing children attending a different school. Only toys used by typically developing children of
the same chronological age as the participants were considered. Third, each toy’s store packaging had a suggested age
range and only toys in which the age range overlapped with the participants’ age were considered. The final list
contained four sets of toys to be further considered for use in the study (i.e., house set, amusement park set, doctor office
set and cooking set with food). These four toy sets were then purchased in order to assess each participant’s preference
for each set of toys