We’re pretty simple. If something sudden happens, we react. We flinch. We stop. We divert all of our attention, unwillingly, to whatever it is that could potentially be posing as a danger to our well being. We will interrupt whatever we’re doing at loud noises or when catching something out of the corner of our eye. It’s our fight or flight instinct. We can’t help it.
Now watch this, and pay particular attention to the animations:
Now if I say: “hunting tiger”?
The animation curves on the Blackberry Playbooks UI are those of a predator, just as it pounces its prey; slooow and then fast!. It’s incredibly disconcerting, causing our lizard brain to subconciously analyze the motions of something as harmless as windows on a screen for signs of danger.
This recalls Apple’s ‘Breathing Status LED Indicator’ (and Dell’s hopeless imitation), though I should mention, just for good measure, that Apple isn’t above reproach; try bringing up your dashboard, and dismiss it. Notice how the widgets fly into your face!, say like a tiger, rather than simply fade away?
Interaction design should for the most part be all but transparent to the user, so here’s my pro tip of the day: try not to emulate our natural predators.
Update: Oddly, the animation curves used for all the marketing material aren’t the ones used in this practical demo: