Two studies examined how nonconservers use the dimensions relevant to quantity in the conservation of substance task. Most nonconservers are very selective in their use of the information provided by these dimensions. Most preschool and kindergarten nonconservers used length to define amount, while ignoring width. This was true regardless of how extreme the transformations were, in what order children saw the transformations, and whether the transformation was begun anew on each trial or continued from trial to trial. The youngest preschool children, however, were not as likely as the older preschoolers to restrict themselves to the length dimension. The results were interpreted as being counter to Piaget's four-step equilibration model of how compensation and conservation develop. (Author/SET)