Information technology (IT) acceptance research has yielded many competing models, each with different sets of acceptance determinants. In this paper, we (1) review user acceptance literature and discuss eight prominent models, (2) empirically compare the eight models and their extensions, (3) formulate a unified model that integrates elements across the eight models, and (4) empirically validate the unified model. The eight models reviewed are the theory of reasoned action, the technology acceptance model, the motivational model, the theory of planned behavior, a model combining the technology acceptance model and the theory of planned behavior, the model of PC utilization, the innovation diffusion theory, and the social cognitive theory. Using data from four organizations over a six-month period with three points of measurement, the eight models explained between 17 percent and 53 percent of the variance in user intentions to use information technology. Next, a unified model, called the Unified Theory of Acceptance and Use of Technology (UTAUT), was formulated, with four core determinants of intention and usage, and up to four moderators of key relationships. UTAUT was then tested using the original data and found to outperform the eight individual models (adjusted R 2 of 69 percent). UTAUT was then confirmed with data from two new organizations with similar

ABSTRACT: Trust is a vital relationship concept that needs clarification because researchers across disciplines have defined it in so many different ways. A typology of trust types would make it easier to compare and communicate results, and would be especially valuable if the types of trust related to one other. The typology should be interdisciplinary because many disciplines research e-commerce. This paper justifies a parsimonious interdisciplinary typology and relates trust constructs to e-commerce consumer actions, defining both conceptual-level and operational-level trust constructs. Conceptual-level constructs consist of disposition to trust (primarily from psychology), institution-based trust (from sociology), and trusting beliefs and trusting intentions (primarily from social psychology). Each construct is decomposed into measurable subconstructs, and the typology shows how trust constructs relate to already existing Internet relationship constructs. The effects of Web vendor interventions on consumer behaviors are posited to be partially mediated by consumer trusting beliefs and trusting intentions in the e-vendor. KEY WORDS AND PHRASES: Customer relationships, human issues in e-commerce, Internet consumers, trust.

ABSTRACT: This paper aims to predict consumer acceptance of e-commerce by proposing a set of key drivers for engaging consumers in on-line transactions. The primary constructs for capturing consumer acceptance of e-commerce are intention to transact and on-line transaction behavior. Following the theory of reasoned action (TRA) as applied to a technology-driven environment, technology acceptance model (TAM) variables (perceived usefulness and ease of use) are posited as key drivers of e-commerce acceptance. The practical utility of TAM stems from the fact that e-commerce is technology-driven. The proposed model integrates trust and perceived risk, which are incorporated given the implicit uncertainty of the e-commerce environment. The proposed integration of the hypothesized independent variables is justified by placing all the variables under the nomological TRA structure and proposing their interrelationships. The resulting research model is tested using data from two empirical studies. The first, exploratory study comprises three experiential scenarios with 103 students. The second, confirmatory study uses a sample of 155 on-line consumers. Both studies strongly support the e-commerce acceptance model by validating the proposed hypotheses. The paper discusses the implications for e-commerce theory, research, and practice, and makes several suggestions for future research.

Despite the inherent risk arising from separating buyers and sellers, networked online marketplaces are proliferating. We describe how online auction marketplaces take advantage of institutional structures to build buyer trust in auction sellers, mitigate risk, increase satisfaction, and promote transaction intentions. It is hypothesized, based on institutional trust (Zucker 1986), that buyer trust in auction sellers can be increased, beyond past experience with sellers, through structural assurances, such as buyer-driven certification, auction house escrows, and credit card guarantees. We examined buyer transaction intentions, mediated by trusting beliefs, risk reduction, and satisfaction. The model is tested with 274 buyers in Amazon’s online auction marketplace. The results support the hypotheses, highlighting the importance of institution-based trust in online networks. Implications are discussed. Keywords: Institution-based trust, online auctions, institutional structures, certification, escrows, third-party guarantees

The Technology Acceptance Model (TAM) represents an important theoretical contribution toward understanding IS usage and IS acceptance behaviors [6, 19]. However, as noted by several IS researchers [cf: 4, 5, 6, 9, 14], TAM is incomplete in one important respect: it doesn't account for social influence in the adoption and utilization of new information systems. Davis [4] and Davis et al. [6] noted that it is important to account for subjective norm (SN), the construct denoting social influence. However, they observed that the conceptualization of SN based on TRA (Theory of Reasoned Action) has theoretical and psychometric problems. Specifically, they observed that it is difficult to distinguish if usage behavior is caused by the influence of referents on one's intent or by one's own attitude. They suggested that this problem may be circumvented by using an alternative theoretical basis for conceptualizing SN, specifically in terms of Kelman's [10, 11] processes of social influence (compliance, identification and internalization). Within the context of organizational enterprisewide implementation and adoption of collaboration and communication technologies, this study establishes theoretical and empirical bases for the above conceptualization originally suggested by Davis and his colleagues. The construct of social influence is operationalized in terms of Kelman's processes of internalization, identification and compliance. Analyses of field study data provide evidence of the reliability and validity of the proposed constructs, factor structures and measures. The findings enable future researchers to account for social influence in further investigating TAM.

One often meets the argument that the adoption of mobile Internet services is difficult to understand due to a lack of relevant research. However, much research has already been conducted on the adoption of basic mobile and traditional Internet services that are likely to converge into the services provided by the mobile Internet. In this article, we try to categorize four research directions relevant in understanding mobile Internet service adoption. We argue that because mobile Internet services are new, a lack of studies directly investigating the adoption these services is to be expected. However, we also argue that existing research directions provide valuable points of departure for further investigating and understanding the adoption of mobile Internet services. In particular, we suggest a cross disciplinary integration of the findings of four different research directions may improve our understanding of the basic mechanisms of individuals' adoption of mobile Internet services. In this article, we exemplify such an integration by suggesting how traditional adoption models in information systems research, such as the technology acceptance model or the theory of planned behavior, may be modified and extended when applied to study the adoption of mobile Internet services. 1.

Even though the literature on the adoption and use of mobile services is quite extensive, surprisingly few studies are found applying traditional models of ICT adoption such as the technology acceptance model. This suggests different perspectives are applied in studies of mobile ICT adoption and traditional ICT adoption. With the introduction of 3G services, a convergence of mobile services and traditional Internet services is expected. Thus, traditional models of ICT adoption may be applied improving our understanding of the adoption of these services. However, studies of the use and adoption of mobile services indicate that traditional adoption models need to be extended and modified when applied to mobile services. In this study, we apply a modified version of the decomposed theory of planned behavior to the adoption behavior of early adopters of mobile commerce services. The study shows that the extended and modified model has good fit to the early adopter data, and that it explains 49 percent of the early adopters' intentions to use mobile commerce services. The model may be used as a basis for industry players' evaluation of the adoption potential of new mobile services.

This research examines the impact of primitive affective reactions to information technology on subsequent cognitive reactions and behavioral intention on IT use, and the potential change of such impact over time. We ground our work in theories of psychology and information systems and propose a theoretical model in which the user’s perceptions regarding the affective quality of an IT influences cognitive reactions and behavioral intention to use IT. The model was validated by surveys in two field studies of 226 and 196 college students, respectively, who were asked to evaluate a course management system, WebCT. The first study occurred during weeks 3 and 4 of the spring 2004 semester, when subjects were getting familiar with WebCT for their classes. The second study ran during weeks 11 and 12 of the same semester, when WebCT had been used quite intensively in the classes. The theoretical model is supported by both studies, indicating that the impact of perceived affective quality persists, even when subjects ’ familiarity with and use of the IT increases. Our research identifies perceived affective quality as another, more-fundamental, and sustained source of user intention of IT use that has not been widely recognized yet. From a theoretical perspective, this research breaks the conventional cognition-driven paradigm of studying user reactions to technology and calls for attention to affect and emotion in examining people’s everyday, normal interactions with IT. Practically, the research provides empirical evidence for IT designers, trainers, and stakeholders to better strategize their resources and emphases.

This paper presents an extension to the technology acceptance model (TAM) and empirically examines it in an enterprise resource planning (ERP) implementation environment. The study evaluated the impact of one belief construct (shared beliefs in the benefits of a technology) and two widely recognized technology implementation success factors (training and communication) on the perceived usefulness and perceived ease of use during technology implementation. Shared beliefs refer to the beliefs that organizational participants share with their peers and superiors on the benefits of the ERP system. Using data gathered from the implementation of an ERP system, we showed that both training and project communication influence the shared beliefs that users form about the benefits of the technology and that the shared beliefs influence the perceived usefulness and ease of use of the technology. Thus, we provided empirical and theoretical support for the use of managerial interventions, such as training and communication, to influence the acceptance of technology, since perceived usefulness and ease of use contribute to behavioral intention to use the technology. # 2003 Elsevier B.V. All rights reserved.

Two complementary mathematical models for attitude formation are considered: Starting from the model of Weidlich and Haag (1983), which assumes indirect interactions that are mediated by a mean field, a new model is proposed, which is characterized by direct pair interactions. Three types of pair interactions leading to attitude changes can be found: First, changes by some kind of avoidance behavior. Second, changes by a readiness for compromises. Third, changes by persuasion. Different types of behavior are distinguished by introducing several subpopulations. Representative solutions of the model are illustrated by computational results.