Three studies of naming in children and in aphasic patients were conducted in order to determine the kinds of errors made in the naming of objects, parts of objects, and various kinds of symbols, and to evaluate the contribution of operativity to the ease of naming such elements. Operativity refers to the extent to which elements can be transformed and involved in a variety of sensory and motor schemes. It was found that operativity of depicted elements makes a significant contribution to ease of naming for both groups of subjects. However, children and aphasic patients made different types of naming errors. In the case of naming of symbols, the categories easiest for aphasics to name proved the