Present research centers on the processes involved in the perception and identification of alphanumeric characters, character strings and pictures. In the perceptual realm, the specific focus is on the nature of partial perceptual information and how this information directs subsequent processing. In the cognitive realm, the specific focus is on the nature of the information which automatically becomes available from the initial perception of a written word or a picture. The goal of these projects is a mathematical description of the processes involved in perceiving pictures and words.