We introduce the concept of the Temporal Thumbnail, used to quickly convey information about the amount of time spent viewing specific areas of a virtual 3D model. Temporal Thumbnails allow for large amounts of time-based information collected from model viewing sessions to be rapidly visualized by collapsing the time dimension onto the space of the model, creating a characteristic impression of the overall interaction. We describe three techniques that implement the Temporal Thumbnail concept and present a study comparing these techniques to more traditional video and storyboard representations. The results suggest that Temporal Thumbnails have potential as an effective technique for quickly analyzing large amounts of viewing data. Practical and theoretical issues for visualization and representation are also discussed.