On/off switches are UI elements that prompt users to choose between 2 mutually exclusive options, always have a default value, and provide immediate results.
Direct-manipulation UIs support interaction with visible objects of interest via physical, reversible, incremental actions that receive immediate feedback.
Selecting a precise value using a slider is a difficult task requiring good motor skills, even if the slider is well designed. If picking an exact value is important to the goal of the interface, choose an alternate UI element.
Although its individual features weren't new, the Mac offered integration, the expectation of a GUI, and interface consistency. Is the iPhone the Mac of mobile?
Macintosh-style interaction design has reached its limits. A new paradigm, called results-oriented UI, might well be the way to empower users in the future.
Despite posing well-known risks, websites continue to feature poorly designed scrollbars. Among the ongoing problems that result are frustrated users, accessibility challenges, and missed content.
User interface guidelines for when to use a checkbox control and when to use a radio button control. Twelve usability issues for checkboxes and radio buttons.