Seite - 66 - in Applied Interdisciplinary Theory in Health Informatics - Knowledge Base for Practitioners

Figure 1. Technology Acceptance Model (TAM) [8]. A number of TAM extensions have been proposed to overcome some limitations in the original model. Several studies added single variables to the original TAM to increase the predictive power of the model, such as individual user factors, organizational readiness, or trust - an overview is given by Holden [8]. TAM2 by Venkatesh & Davis (2000) [9] extended TAM with variables that were seen as influencing perceived usefulness or user acceptance, such as subjective norm, image, voluntariness of use, or job relevance. Further extensions of TAM, such as TAM 3 [10], added other concepts such as computer anxiety or enjoyment. The TAM theory of technology acceptance and use has gained significant popularity in the field of technology acceptance research and is considered a “key model” [11] or “gold standard” [8] in understanding predictors for IT acceptance. A PubMed query on “Technology acceptance model” retrieved 340 papers (search done on 7 June 2018), showing the popularity of TAM also within health informatics research. 1.2. Unified Theory of Acceptance and Use of Technology (UTAUT) The Unified Theory of Acceptance and Use of Technology (UTAUT) was published by Venkatesh and Davis in 2003 [2]. UTAUT is based on an analysis and comparison of eight technology acceptance models, among them TAM, TAM2, the Theory of Reasoned Action and the Diffusion of Innovation Theory. The aim was to synthesize the multitude of available models on technology acceptance into one unified model. The aim of UTAUT is to assess the likelihood of success for new technologies and to understand drivers of acceptance [2]. UTAUT describes four key variables: Performance Expectancy, Effort Expectancy, Social Influence, and Facilitating Conditions. Performance Expectancy is the expectation of a user that the system will be useful for the job; it corresponds to Perceived Usefulness in TAM. Effort Expectancy is the expectation that the system is user friendly and easy to use; it corresponds to Perceived Ease of Use in TAM. Social influence is defined as the degree to which a user perceives that important others believe he or she should use the new system. Facilitating Conditions are defined as the degree to which a user believes that an organizational and technical infrastructure exists to support system use. In UTAUT, Behavioral Intention to Use the technology is determined by Performance Expectancy, Effort Expectancy, and Social Influence. Actual Usage is then determined by Behavioral Intention to Use and the Facilitating Conditions. Gender, age, E.Ammenwerth /TechnologyAcceptanceModels inHealth Informatics: TAMandUTAUT66