Humans form opinions and justify different points of view by ex- changing arguments and knowledge. Likewise to human-human interaction, the way arguments are presented infuence the user’s willingness to engage into a critical refection. Especially when interacting with conversational agents the user’s engagement and motivation are important factors and highly infuence the success or failure of such a mixed team. To maintain the users’ trust and satis- faction, the users’ perception of the respective system is an important indicator. Thus, this work investigates the design of a cooperative argumentative dialogue system using a virtual avatar compared to a non-avatar interface by evaluating a crowdsourcing study conducted with 84 participants. The results indicate, that the avatar system is perceived as signifcantly more appealing and natural and thus, engaging which also infuences the acceptance and perception of the quality of presented arguments. Furthermore, we found that the presence of the avatar often led to an increase in the anticipated level of conversational profciency similar to that of a human interlocutor. Therefore,
this work provides important insights for the design of future cooperative argumentative virtual avatar interfaces.