Abstract
What items contribute to user satisfaction with large ubiquitous systems? This article reports on studies that seek answers to this question through the context of London Transport's Oyster system. Two studies are presented. In the first, an existing quantitative instrument (End-User Computing Satisfaction, or EUCS), originally developed to evaluate satisfaction with mandatory use systems, is used to measure satisfaction through a small survey. In the second, Twitter data are used to demonstrate how broader items contribute to user satisfaction. The first study demonstrates that the EUCS constructs of Content, Accuracy, Format, Ease of use, and Timeliness are still statistically valid, although discriminant problems exist. However, the second study, the analysis of Twitter activity, reveals that Content and Format are not relevant to Oyster users, and that Accuracy and Timeliness are conceptualized very differently. Moreover, Ubiquity emerges as an important item contributing to satisfaction, or in some cases dissatisfaction.