“…Some factors that may influence preference assessment outcomes include: (a) the number of stimuli included in an array (Fisher et al, 1992), (b) the type of response measure (engagement or approach; Rech, 2012), (c) motivating operations (Gottschalk, Libby, & Graff, 2000), and (d) the composition of the array. To date, five studies have examined the effects of array composition by assessing the preference for one stimulus class over another with individuals with intellectual and developmental disabilities (IDD; Andakyan, Fryling, & Benjamin, 2016;Bojak & Carr, 1999;Conine & Vollmer, 2018;DeLeon, Iwata, & Roscoe, 1997;Fahmie, Iwata, & Jann, 2015). DeLeon, Iwata, and Roscoe (1997) were the first to evaluate the displacement of one stimulus class over another.…”