In response to the rapid changes in users' requirements, a new generation of information systems (IS), namely, agile IS, has emerged. Agile IS, defined as information systems developed using agile methods, are characterized by frequent upgrades with a small number of new features released periodically. The existing research on agile IS has mainly focused on the developers' perspective with little research into end users' responses to these agile IS. Drawing upon the tripartite model of attitude, the status quo and the omission bias theories, and the availability heuristic, we propose a model that utilizes constructs from the unified theory of acceptance and use of technology, the IS continuance model, habit, and individual differences to examine the drivers of user acceptance of agile IS. Further, we investigate not only users' intentions to continue using the agile IS but also their intentions to use new features when they are released, which is a surrogate for the ultimate success of agile IS. Data from 477 users of an agile IS showed that users' level of comfort with constant changes, the facilitating conditions provided, and users' habit are predictors of both types of intentions, with users' level of comfort with constant changes being the strongest predictor. Users' intentions to continue using agile IS are also determined by users' satisfaction with and perceived usefulness of the past upgrades. Finally, users who are innovative are more likely to use future releases of new features. The present work fills a gap in the software engineering literature and contributes a technology acceptance model specific to agile IS, which are becoming a mainstay of companies' IT portfolio in a fast-changing business environment.
Efforts to develop measures of Internet commerce success have been hampered by (1) the rapid development and use of Internet technologies and (2) the lack of conceptual bases necessary to develop success measures. In a recent study, Keeney (1999) proposed two sets of variables labeled as means objectives and fundamental objectives that influence Internet shopping. Means objectives, he argues, help businesses achieve what is important for their customers—fundamental objectives. Based on Keeney's work, this paper describes the development of two instruments that together measure the factors that influence Internet commerce success. One instrument measures the means objectives that influence online purchase (e.g., Internet vendor trust) and the other measures the fundamental objectives that customers perceive to be important for Internet commerce (e.g., Internet product value). In phase one of the instrument development process, we generated 125 items for means and fundamental objectives. Using a sample of 199 responses by individuals with Internet shopping experience, these constructs were examined for reliability and validity. The Phase 1 results suggested a 4-factor, 21-item instrument to measure means objectives and a 4-factor, 17-item instrument to measure fundamental objectives. In Phase 2 of the instrument development process, we gathered a sample of 421 responses to further explore the 2 instruments. With minor modifications, the Phase 2 data support the 2 models. The Phase 2 results suggest a 5-factor, 21-item instrument that measures means objectives in terms of Internet product choice, online payment, Internet vendor trust, shopping travel, and Internet shipping errors. Results also suggest a 4-factor, 16-item instrument that measures fundamental objectives in terms of Internet shopping convenience, Internet ecology, Internet customer relation, and Internet product value. Evidence of reliability and discriminant, construct, and content validity is presented for the hypothesized measurement models. The paper concludes with discussions on the usefulness of these measures and future research ideas.