Abstract
In the previous research (Okuda, 2007), recognition of college student subjects concerning
developmental change of infants, children, adolescents, middle-aged, elderly-people were examined applying the
fuzzy set theory. But there were few available data concerning recognition of developmental change in various
functions of subjects with different ages. Therefore, these studies were designed to examine those problems. To
investigate the difference of recognition concerning developmental change by the age of subjects, young person
subjects (18-22), middle-aged subjects (40-59), and elderly subjects (65+) were asked to evaluate 5 development
estimation item groups to see to what degree 1,3, 5, 10, 20, 40, 60 and 80 years old people would be able to
perform independently and adequately. Average scores of 5 item groups of 60 years old of the middle-aged and the
elderly groups were higher than average scores of the young person group. The possible reasons concerning the
difference of recognitions of developmental change by the age of subjects are discussed.
