The development of scanning strategies and their relation to visual differentiation.

Abstract The oculo-motor activity of 78 children between 3 and 9.6 years of age was recorded during a task of perceptual differentiation. The stimuli were six drawings of pairs of houses; the two houses were identical on three pairs, they differed by the properties of one, three, or five windows on the other three pairs. Instructions were given to answer “same” or “different” as soon as a decision was reached. The corneal reflection of the stimuli was filmed during the performance, thus allowing the experimenter to measure the location, duration, and sequence of eye fixations between the moment a stimulus appeared and the moment the judgment was uttered. Results were treated by analysis of variance. Under 6 years of age, the children scanned only a limited part of each stimulus and judged two houses to be identical or different on the basis of insufficient information. An appropriate method of paired comparisons appeared at age 5 and was adopted by the great majority of children over 6. An attempt was made to relate the information gathered by visual scanning and the judgment uttered, and to determine the criteria of identity and of difference, and their evolution with age.