ABSTRACT

Many account for the capacity of infants, young cnildren, and animals to discriminate small numerosities by an appeal to subitizing (Chi & Klahr, 1975; Davis & Perusse, 1988; von Glasserfeld, 1982; Klahr & Wallace, 1973; Rumbaugh, Savage-Rumbaugh, & Hegel, 1987; Shipley & Shepperson, 1990). Despite the central role attributed to this process, there has never been an explicitly formulated model of it. Kaufman, Lord, Reese, and Volkman (1949) coined the term subitizing for the process used by adults to give rapid numerosity judgments for small arrays of simultaneously presented dots.