Proceedings of the Annual Meeting of the Cognitive Science Society

We are surprised when events violate our intuitive physicalexpectations. Even infants look longer when things seem tomagically teleport or vanish. This important surprise signalhas been used to probe what infants expect, in order to studythe most basic representations of objects. But these studiesrely on binary measures – an event is surprising, or not. Here,we study surprise in a more precise, quantitative way, usingthree distinct measures: we ask adults to judge how surprisinga scene is, when that scene is surprising, and why it is surpris-ing. We find good consistency in the level of surprise reportedacross these experiments, but also crucial differences in theimplied explanations of those scenes. Beyond this, we showthat the timing and degree of surprise can be explained by anobject-based model of intuitive physics.