THE EFFECTS OF PICTORIAL AND VERBAL INSTRUCTIONAL MATERIALS ON THE OPERATIONAL PERFORMANCE OF DEAF SUBJECTS1

ness of pictorial and verbal information in printed instructional materials for deaf subjects. Four types of instructional formats were pre-pared, varying in proportion of pictorial and verbal information: (a) all pictorial; (b) pre-dominantly pictorial, with some ancillary verbal information; (c) all verbal; and (d) pre-dominantly verbal, with some ancillary pictorial information. Each format was given to a separate group of deaf college students. The instructional materials described sequences of operational procedures to be carried out by subjects on a complex control-display apparatus. Performance was measured by task completion time and error rate. Result