Described are three experiments which probed children's sensitivity to structure or organization in visual patterns. Each experiment employed a different paradigm (complexity judgment, discrimination learning, recognition learning, and memory) in order to tap different aspects of children's use of structural information. Subjects were children in kindergarten through sixth grade as well as university students. Major findings were (1) indices of sensitivity to visual organization show dramatic changes with age; (2) children's sensitivity to visual structure depends upon the type of structure; and (3) whether or not sensitivity to structure is revealed depends upon the experimental task. (Author/MS)