“…Previous studies, including some with tabletop settings, have shown that children of that age level and even much younger children readily demonstrate visual-visual equivalence (e.g., Barnes, Browne, Smeets, & Roche, 1995;Barnes et al, 1990;Carpentier, Smeets, & Barnes-Holmes, 2002;Devany et aI., 1986;Lazar et aI., 1984;Sidman et aI., 1986;Smeets & Barnes-Holmes, 2003;Whetherby, Karlan, & Spradlin, 1983; but see Saunders, Drake, & Spradlin, 1999). This discrepancy could be related to the fact that the preexperimental tasks trained and tested nonarbitrary stimulus control while experimental tasks required arbitrary stimulus control.…”