Modelling User-Centered-Trust (UCT) in Software Systems. Interplay of trust, affect and acceptance model Zahid Hasan, Alina Krischkowsky, and Manfred Tscheligi Christian Doppler Laboratory for Contextual Interfaces HCI & Usability Unit, ICT&S Center, University of Salzburg Sigmund-Haffner-Gasse 18, 5020 Salzburg, Austria firstname.lastname ´ @sbg.ac.at Abstract. Even though trust is a frequently articulated topic in soft- ware technology literatures, yet the user centered point of view of trust is hardly discussed. How users perceive the trustworthiness of software sys- tems is not trivial, in fact, if a user cannot trust a program to execute on his behalf, then he should not run it [36]. This paper identifies a potential lack in examination of trust in software systems from user’s perspective and aims to develop a conceptual User-Centered-Trust (UCT) framework to model it. This model integrates both Technology Acceptance Model (TAM) and trust under Theory of Reasoned Action (TRA) nomological network. In order to integrate them, trust has been conceptualized as an attitude towards the usage of the systems having two distinct dimensions: cognitive and affective. Keywords: Trust, Acceptance model, Technology 1 Introduction The advent of World Wide Web (WWW) and the emergence of e-commerce dur- ing the 90s [23] introduced new types of buying-selling behaviors over the Inter- net which differ from traditional ‘face-to-face’ interaction. In this new paradigm trust is considered as an essential component [2]. A considerable number of trust models and frameworks have been proposed during past decades. However, the trust targets in most of these studies are humans (e-vendor or organizations), and the nature as well as the role of trust in technological artifacts remains un- clear [71]. What has been generally absent from these investigations is a focus on the effects of trust placed in the information technology (IT) artifacts-hardware and software systems [69]. Trust in IT is an important concept because people today rely on IT more than ever before [48], although, the nature of trust in technological artifacts is still an under-investigated and not well understood topic [71]. Researchers debate whether or not technological artifacts can be an object of trust [71], and if it is valid to ascribe human characteristics to technological artifacts [71]; [10]; [48]; [49]; [13].