Modelling serial position curves with temporal distinctiveness.

We offer a critique of the temporal distinctiveness model of serial position effects (Nairne, Neath, Serra, & Byun, 1997). The temporal distinctiveness model combines a precise definition of stimulus distinctiveness with a memory perturbation process. The critique is empirically motivated-we show that with a more complete analysis, the temporal distinctiveness model does not adequately account for Nairne et al.'s experimental data. To better account for the data, we independently modified two components of Nairne et al.'s model: the mathematical form of the definition of temporal distinctiveness and the mathematical form of the mapping from distinctiveness to free-recall probabilities. Both of these modifications provided for better fits. Yet both Nairne et al.'s definition and our modified definition are fairly arbitrary. We show that a significant challenge to this approach is to find theoretically motivated constraints of the temporal distinctiveness model while providing for adequate fits to data.