I'LL CALL YOU TOMORROW

The second requirement for Flow is fast, accurate feedback. It’s interesting that the definition of interactive is "of or relating to a two-way electronic or communications system in which response is direct and continual." – in other words, fast, accurate feedback.

Primitive feedback in a video game context, is "Yikes!" I just blew up! Or, back to the caveman, the tiger leapt at him and he managed to get out of the way. His fast, accurate feedback was that he knew he was still alive when the tiger hit the ground.

Of course fast, accurate feedback doesn’t have to be a matter of life or death. In applications, The very definition of interactive calls for feedback that is "...direct and continual." Given that, I can think of many supposedly "interactive" applications that hardly qualify because of their slow performance and long latency between action and response. Web applications are especially bad. We all hate long downloads, not just because of the time it takes, but because we seldom have any clue as to how long we are going to have to wait.

All this translates into a simple rule of thumb for life and design. In all things, be informative.