Several aspects of memory development were discussed within the framework of different types of memory research: the development of representational abilities; the development of the propensity to reprsent; the development of mnemonic strategies; the development of a general information base; the development of familiarity with different types of stimulus representation; and the development of the cognitive operative system. To understand memory performance in a particular task, the investigator must ask what role the manner in which the stimuli are presented plays; what subjects do when presented with the stimuli; what the characteristic of the assimilative/accommodative interaction between stimuli and organism are; and what the organism has to do to show memory.