UI Responsiveness: Instantaneous, Immediate, Continuous, Captive

InformIT: UI Responsiveness: Instantaneous, Immediate, Continuous, Captive > Instantaneous Responsiveness: "Beyond just measurable timings, perceived duration and user tolerance are important considerations when optimizing the user experience of your website or solution. Specifically, when you're coding a website or building applications, you need to take into account how your solution will expend the user’s time. Steven C. Seow discusses the various situations and four classes of responsiveness for different form of interactions."