||Previous researchers and practitioners have investigated information systems (IS) acceptance/adoption, in a wide range of organizational contexts and subject domains from different perspectives. However, the prominent model frameworks seem to view the same phenomenon from specific and restricted 'lenses'. Therefore, the objectives of this research study are to: (1) examine and develop an integrated model explaining the phenomenon from several different perspectives within a particular organizational context; and (2) examine whether the model explains adoption behaviors over time. An integrated model, composed of (1) Social perspective (subjective norm), (2) Technology perspective (perceived usefulness and perceived ease of use), and (3) The-self (computer self-efficacy) perspective better explains information technology acceptance than previous models commonly used in IS research. Moreover, the longitudinal field study shows that key intention motivators diminish in effect over a prolonged use of time. This thesis concludes with implications for both academics and practitioners in the design and implementation of information technology strategies.