International Journal of Man-Machine Studies
(1992) 36, 375-393. [Published Version
HCIL-89-18, CS-TR-2352, CAR-TR-472
This article describes four different user interfaces supporting scheduling two-state (ON/OFF) devices over time periods ranging from minutes to days. The touchscreen-based user interfaces including a digital, 12-h clock, 24-h linear and 24-h dial proto
types are described and compared on a feature by feature basis. A formative usability test with 14 subjects, feedback from more than 30 reviewers, and the flexibility to add functions favour the 24-h linear version.