Week 4: The bar is not the process

Determinate progress, where the system commits to a number it does not have, and the design space that opens once you accept that.

9 March 2027

A progress bar makes a promise a system is usually in no position to keep. It has to name a fraction before it knows the denominator, so it estimates, and then it has to keep the estimate moving while the estimate changes.

Once you accept that the bar is not a readout of the process, it becomes a piece of design with its own variables. Harrison and colleagues changed how long a fixed duration felt by changing only how the bar animated. The underlying process was identical in every condition.