In 1944, psychologists Fritz Heider and Marianne Simmel created a short, 90-second animated film depicting two triangles and a circle moving around a box with a hinged opening, and reported how subjects viewing the film anthropomorphized the three shapes as characters with humanlike goals, emotions, and social relationships. In this paper we model this type of high-level reasoning as a process of probability-ordered logical abduction (Etcetera Abduction), where the interpretation of the film is incrementally constructed by disambiguating observed movements in the contexts of multiple running hypotheses. We describe a target interpretation and knowledge base that we used in a series of experiments to investigate the effects of varying the window size and number of running hypotheses maintained during the interpretation.
