Effects of Adaptivity and Other External Variables on Mobile Service Adoption Ebru Polat Bogazici University ebrupolat1983@gmail.com Nuri Basoglu Bogazici University nuri.basoglu@boun.edu.tr Tugrul Daim Portland State University tugrul@etm.pdx.edu ABSTRACT User Interface between user and information systems has a great role in system adoption. Based on technology acceptance model, acceptance of a system is explained as a function of perceived usefulness and perceived ease of use. Since there are several external variables that have an impact on perceived usefulness and perceived ease of use, the content and interface design of every single application should be addressed accordingly to enhance users intention to use the system. We propose that adding adaptive features into systems may be one of the approaches to address this phenomenon. This paper identifies external variables including adaptive behavior impacting acceptance of mobile reservation system through two prototypes. 1. INTRODUCTION The objective of this study is to figure out potential external variables that may have an influence on perceived ease of use, perceived usefulness and indirectly on behavioral intention in mobile system acceptance and to explore effects of those variables, primarily adaptivity and their relationships with each other through the limited interface of a mobile device. We expect that different external variables have different impacts on perceived ease of use and perceived usefulness and that adaptivity, one of the external variables that we mostly dwell upon, enhance both ease of use and usefulness and indirectly behavioral intention in mobile system adoption. Also, those external variables are expected to have effect on each other which influences mobile IS acceptance through mediation of perceived ease of use, perceived usefulness and behavioral intention. Figure 1  Research Flow In order to explore our hypothesis, we developed 2 prototypes for a mobile service application with additional features integrated into the second prototype to be able to compare external variables effects. Figure 1 depicts the research flow. 2. LITERATURE REVIEW Research has several streams related to our objectives. There is a significant amount work done in the adoption and specifically adoption of information systems. There is a growing amount of work focusing on services including mobile services and finally equal amount of work that has focused on the adaptivity. Review of the technology adoption literature reveals that there are several user and service related characteristics that impact users intentions to use an information system. Chalmers proposed that cognitive factors and concepts should be taken into consideration when developing user interfaces [1]. According to Bederson interfaces should keep us on the flow, concentrating on our work [2]. Wood, Cox and Cheng mentioned about importance of attention and propose 8 design issues to consider for developing attentionaware systems [3]. Murrell explained design principles that should be taken into account for use in a multi lingual, multi cultural environment [4]. Kamppuri, Bednarik, Tukiainen explored culture-related studies to analyze occurrences and characteristic of culture studies in HCI [5]. Bassam and Mesbah examined the effect of Proceedings of the 42nd Hawaii International Conference on System Sciences - 2009 1 978-0-7695-3450-3/09 $25.00 © 2009 IEEE