Abstract—When using a robot or a screen agent, elderly users might feel more enjoyment if they experience a stronger social presence. In two experiments with a robotic agent and a screen agent (both n=30) this relationship between these two concepts could be established. Besides, both studies showed that social presence correlates with the Intention to Use the system, although there were some differences between the agents. This implicates that factors that influence social presence are relevant when designing assistive agents for elderly people. I. INTRODUCTION XPLORING the possibilities for using robots and screen agents in eldercare [1], we face not only technological issues but also challenging questions concerning the way elderly people are coping or not coping with this new technology [2-5]. In our research, we address some of those questions by exploring the factors that may influence acceptance of a conversational robot by elderly users [6]. We not only have to deal with the fact that the user characteristics of elderly people differ from the user groups that are addressed in most acceptance studies; we are also facing a type of technology that brings about different aspects [7]. For example, for many users a robot or screen agent may be experienced as a personality that one might or might not appreciate, rather than a piece of technology. Besides, robots and screen agents could have ‘hedonic’ aspects: users might actually feel the same enjoyment they would feel when playing a game or having a pleasant conversation with a person. And it might very well be that the more natural and ‘human like’ this conversation is, the more enjoyment a user would feel and the more this user would feel encouraged to actually use this technology. In technology acceptance models, enjoyment is sometimes incorporated as ‘Perceived Enjoyment’, defined as ‘the extent to which the activity of using the system is perceived to be enjoyable in its own right, apart from any performance consequences that may be anticipated’ [8]. Most acceptance Manuscript received February 1, 2008. This work was supported in part by the Hogeschool van Amsterdam and in part by the European Commission Division FP6-IST Future and Emerging Technologies under Contract FP6-002020 (Cogniron). Marcel Heerink is with the Instituut voor Information Engineering, Almere, Netherlands (+31-36-5480771; e-mail: m.heerink@hva.nl). Ben Kröse is with the Institute of Informatics, University of Amsterdam, Amsterdam, the Netherlands, (e-mail: Krose@science.uva.nl). Vanessa Evers and Bob Wielinga are with the Human Computer Studies Lab at the University of Amsterdam, the Netherlands (email: evers@science.uva.nl, wielinga@science.uva.nl) models however, are developed within the context of utilitarian or productivity-oriented systems and Perceived Enjoyment is usually not incorporated as a major influence. However, for hedonic, or pleasure oriented systems it seems to be a crucial factor [9]. In the context of acceptance of an assistive social robot by elderly users [10] we found strong indications that Perceived Enjoyment is a major influence on the Intention to Use a system. If this enjoyment can be related to the feeling of really having contact with a mechanical but social entity, this would mean that a stronger sense of ‘Social Presence’ would lead to a stronger feeling of enjoyment. The goal of this paper is to try to establish these relationships: Social Presence being a determinant of enjoyment and enjoyment being a determinant of acceptance. This acceptance is to be measured both by the Intention to Use the system and by actual use of it. After describing related research and theoretical concepts, we will explain how we set up experiments with a robot and a screen agent to gather data on Social Presence, enjoyment, Intention to Use and actual (long term) usage of the technology. After analyzing the results of this experiment, we will establish the preliminary position of Social Presence, and Perceived Enjoyment in an acceptance methodology and set out a path for further development of an appropriate model. II. THEORETICAL FRAMEWORK In this section we will explore the used theoretical concepts by discussing related research. We will subsequently discuss robotic technology being used in eldercare, on applying acceptance methodology to robots, on Perceived Enjoyment and on Social Presence. A. Robots and screen agents in eldercare Projects addressing the development of conversational robots for experiments in eldercare are either focussing on possibilities and requirements or on measuring the responses tot it by performing experiments with specific robots. An example of the latter is the research done with a seal shaped robot (Paro) [11, 12]. These experiments showed that a robot could have the same beneficial effect on elders that a pet can have, making them feel happier and healthier. A more recently developed robot with similar pet-like functionalities is the Huggable [13]. Another example of a robot developed specifically for eldercare experiments is ‘nursebot’ Pearl, a robot that could The Influence of Social Presence on Enjoyment and Intention to Use of a Robot and Screen Agent by Elderly Users Marcel Heerink, Ben Kröse, Vanessa Evers, Bob Wielinga E Proceedings of the 17th IEEE International Symposium on Robot and Human Interactive Communication, Technische Universität München, Munich, Germany, August 1-3, 2008 978-1-4244-2213-5/08/$25.00 ©2008 IEEE 695