Autonomous adaptation of software agents in the support of human activities Esteban Guerrero 1 , Ming-Hsin Lu 2 , Hsiu-Ping Yueh 2 , and Helena Lindgren 1 1 Computing Science Department, Ume˚ a University, Sweden {esteban, helena}@cs.umu.se 2 Human Performance and Technology Lab., National Taiwan University, Taiwan {f01630002,yueh}@ntu.edu.tw Abstract. This paper is aimed at formalizing the interplay among a person to be assisted, an assistive agent-based software, and a caregiver. We propose principles that agents should follow in such interplay, this principles may have impact in different agent-based assistive technology. We propose a mechanism to integrate individual’s information into the final decision-making process of an agent. Moreover, we endow agents with mechanisms for evaluating the distance between independent and supported activity execution, the so called zone of proximal development (ZPD) in four scenarios: I) independent activity execution by a person; II) ZPDH activity performance of a person supported by another person (e.g. a therapist); III) the ZPDS representing a potential activities when a person is supported by a software agent; and IV) the ZPDH+S when a person is supported by a caregiver and a software agent. Formal argu- mentation theory is used as foundation. Our formal models were tested using a prototype using augmented reality as assistive software. A pilot study with older adults and health-care personnel was performed and formal and empirical results are presented. Keywords: Argumentation theory · Rational agents · Assistive technol- ogy · Human activity · Activity theory. 1 Introduction This paper is aimed at investigating assistive technology using argumentation- based agents and the interplay with individuals that require physical assistance and their caregivers. We present formal and empirical results on how intelligent software adapts to support activities of individuals including, those who need assistance and care givers. The focus of the paper is on the provision of human-like characteristics to software agents in order to provide adaptable support, namely common-sense and reflection on action decision. The proposed agent model is oriented to reason about human activities, i.e., identify and interpret activities, and support indi- viduals during the execution of physical activities. To this end, representations of complex activities from Activity Theory [15] were utilized to characterize the