What is the shortest perceivable application response delay?

Question

A delay will always occur between a user action and an application response.

It is well known that the lower the response delay, the greater the feeling of the appli

Answer 1

Persistence of vision is around 100ms so it should be a reasonable visual feedback delay. 110ms should make no difference, as it is an approximate value. In practice you won't notice a delay below 200ms.

Out of my memory, studies have shown that users lose patience and retry an operation after around 2s of inactivity (in the absence of feedback), e.g. clicking on a confirm or action button. So plan on using some kind of animation if the action takes longer than 1s.