Development of working memory: should the Pascual-Leone and the Baddeley and Hitch models be merged?

The data presented by Kemps, De Rammelaere, and Desmet (2000, this issue) appear to have some aspects that fit most readily into our own model (Baddeley & Hitch, 1974), while others appear to support that of Pascual-Leone (1970). We accept that our initial model said little about development and was better able to account for relatively simple memory-based tasks than more complex cognitive activities. More recent elaborations of the model are, however, able to throw new light on the processes underlying cognitive development, offering a better account than that provided by existing neo-Piagetian interpretations. Meanwhile, the addition of a fourth component to the model, namely the episodic buffer, offers a way of dealing with more complex cognitive activities. Given the major differences between our own model and that of Pascual-Leone in basic assumptions, and in theoretical style, we suggest that any attempt to combine the two would be premature.