Interaction between abstract agents: increasing the readability of causal events with animation principles

Abstract

In cognitive psychology, causality studies investigate simple causal relations to understand how people perceive a causal relation between agents. In those experiments, geometric shaped characters are used to examine the causal relations only. However, the actions of characters (or agents) in those experiments were not completely described as causal events by many participants, which might be the result of a shortcoming in the design of agents' actions. We believe we can improve the readability of causal events with animation principles. We created expressive actions by the use of animation principles of anticipation and reaction, which are used to emphasize the meaning of the main action with expressiveness in pre- and post- actions. To analyze the effect of expressivity and its effect on different embodiments of agents, we conducted a user study with 4 animation clips including expressivity (expressive vs. non-expressive action) and embodiment (object vs. robot embodiment) conditions. We analyzed data from 116 adult participants and the results showed that expressive actions significantly increased the readability of interaction between abstract agents in causal events. We also found that the type of embodiment has no effect on readability when we applied expressive actions into their movements.