Proceedings of the Annual Meeting of the Cognitive Science Society

SIAM, a model of structural similarity, is presented. SIAM, along with models of analogical reasoning, predicts that the relative similarity of different scenes will vary as a function of processing time. SIAM's prediction Is empirically tested by having subjects make speeded judgements about whether two scenes have the same objects. The similarity of two scenes with different objects is measured by the percentage of trials on which the scenes are called the same. Consistent with SIAM's prediction, similarity becomes increasingly influenced by the global consistency of feature matches with time. Early on, feature matches are most influential if they belong to similar objects. Later on, feature matches are most influential if they place objects in alignment in a manner that is consistent with other strong object alignments. The similarity of two scenes, rather than being a single fixed quantity, varies systematically with the time spent on the comparison.