Part 4. Responsiveness

Responsiveness is about how the people using the app perceive the time the app takes to do something. The key word in that last sentence is perceive. Perception is relative to the person making the judgment. The time an action takes may always be the same, but depending on mood, time of day, or other activities, that elapsed time can feel, or be perceived to be, wildly different.

Many designers and developers will be familiar with the idea of responsive design, which focuses primarily on the way the UI of an app or website reacts to the space or resources available to it. In this book, I’m using a much broader definition of the term to consider all the ways people using the app can perceive its responsiveness.

It’s common to link ideas about how the app responds with output, as people experience the output of an app through a “filter of responsiveness.” But I draw a distinction between what’s displayed (output), and how it feels while waiting for its display (responsiveness). Responsiveness has ties to more than just output. Context influences it. It can determine the appropriateness of input methods, and it’ll be affected by connectivity and the use of resources.