Cognitive aging research needs to clarify whether or not there are functional or ability declines with aging and, if so, to understand and mediate these declines. Recent research which has demonstrated declines in cognitive functioning with age has involved episodic memory and rehearsal-independent forms of such memory. It is not known how much of this decline can be attributed to physiological, sociocultural, or experiential factors. Continuing, if not increasing, productivity with aging occurs in performance areas requiring expertise such as mathematics or the arts. Tasks that do not require expertise, such as finger tapping, are often used in psychological research. Expertise tasks tend not to be measured in developmental research. Some research has shown paradoxical results for functional skills tests. Although older people were slower at component skills of a task, they were equal in overall task performance. This suggests limitation in the kind of measurement commonly used in cognitive research. It is not known whether expert performance is maintained by compensatory strategies or whether the present componential analysis is incorrect. (ABL)