Perceived performance
Performance is one thing, perceived performance is another. Using different techniques it’s very possible to make things feel faster than reality. But what if perception is reality? Just kidding. Consider the following example: you want to copy a file from A to B and do it using two different applications.
Let’s examine running a task with and without perceived performance.
An example
The task takes exactly 10 seconds to complete. Both apps pop up a dialog with the task status but the app with perceived performance closes the dialog sooner at 90% instead of the excepted 100%.
Wait, what?
It visually shows the task as completed before it actually is. It makes you think it is done before it really is. It is cheating.
YES. And that’s perceived performance for you right there. Perceived performance will make your software feel faster, which in turn will make it faster.