Towards Empirically Validated Ubiquitous Information Systems : Results from a Pretest and Three Empirical Studies

Research on ubiquitous information systems (UIS) has recently gained attention in the IS community. But dedicated empirical instruments that are robust and capture individual characteristics of UIS are still missing. A rather new empirical construct derived from Task-Technology Fit theory was proposed and denoted as Situation-Service Fit (SSF). This paper shows how SSF can be used within the Situational Design Method for IS, a design method tailored to UIS. For this purpose, the SSF instrument is first tested for face validity as well as discriminant and convergent validity. Then, SSF is evaluated as a predictor variable of behavioral intentions to use services that are embedded in UIS. Hereby, also discriminant validity of SSF with regard to perceived usefulness and perceived ease of use is assessed. For this purpose, data from a four-year EU project is used, which includes a pretest and three empirical user studies. Results show that SSF can be a significant predictor of service usage. However, validity issues still exist and thus, further research on the SSF instrument is recommended.