End anchoring in short-term order memory

Temporally grouping lists has systematic effects on immediate serial recall accuracy, order errors, and recall latencies, and is generally taken to reflect the use of multiple dimensions of ordering in short-term memory. It has been argued that these representations are fully relative, in that all sequence positions are anchored to both the start and end of sequences. A comparison of four computational models of serial recall is presented that shows that the extant empirical evidence does not point towards fully relative positional markers, and is consistent with a simpler scheme in which only terminal items are coded with respect to the end of a sequence or subsequence. Results from the application of the models to data from two new experiments varying the size of groups in serially recalled lists support this conclusion.