A dominant theme in cognitive psychology is that prior knowledge in long-term memory has a strong influence on an individual's cognitive processing. Citing numerous memory studies with children, knowledge base effects are presented as part of a broader picture of memory development. Using the sort/recall procedure (asking subjects to group sets of items prior to recall), instructions provided have dramatic effects on the sorting style and recall performance of younger children. With highly salient stimulus materials (categorically related items) and remembering based instructions, third graders form meaningful groups and transfer the organizational strategy to unstructured materials. Rehearsal strategies of third graders also vary as a function of stimulus properties. The data suggest that with developmental advances in component cognitive skills, applying mnemonic strategies requires less effort and becomes increasingly routinized. Complete understanding of memory development requires a longitudinal analysis of children at all stages of mnemonic competence, rather than traditional cross-sectional research designs focusing on particular mnemonic skills. (BS)