User experience (UX) has become a central theme in usercentered design. It draws attention to the experiential side of use and sets new requirements for software design. Waiting and interruptions can be a source of negative experiences with interactive systems. This review paper discusses the subjective experience of time as a part of UX. It also provides advice on how to influence UX through time-considerate design. We start from the psychological theory of time perception and expand this cognitivist model to a direction compatible with affective computing. The outcome describes the interplay between cognition and affect through a concept of subjectively experienced time. We introduce six design guidelines for time-considerate design of everyday applications. Our design implications concern dialogues, progress indicators, and cost-effective system optimization relevant for UX. We point out the need for empirical research to fill in the gaps in the literature, particularly regarding user adjustment and its implications.
Author KeywordsHCI design and evaluation methods; interaction design theory, concepts and paradigms; psychology; user experience; user models.