Regarding the transitions - often times an animated transition is used to mask program latency. Unminimizing a program can use an animation to mask the time it needs to possibly read from an on-disk cache. The use of them is especially evident on phones, which make heavy use of transition effects. Swoop ins and other animations will often give the program around 500 milliseconds before it has to be responsive. It gives the illusion of things working faster than they actually are. With larger memory stores and SSD's becoming more common, many of these animations are no longer absolutely necessary, but on older systems they help tremendously for the user experience.
> Chris Harrison at Carnegie Mellon University in Pittsburgh, Pennsylvania, working with Zhiquan Yeo and Scott Hudson, has shown that animated pop-up download progress bars which use visual illusions make the process seem around 10 per cent faster than it really is.
Apple already uses a a basic visual trick of this kind in its Mac OS X operating system, but Harrison's research suggests such techniques could be used to greater effect.
Regarding the transitions - often times an animated transition is used to mask program latency. Unminimizing a program can use an animation to mask the time it needs to possibly read from an on-disk cache. The use of them is especially evident on phones, which make heavy use of transition effects. Swoop ins and other animations will often give the program around 500 milliseconds before it has to be responsive. It gives the illusion of things working faster than they actually are. With larger memory stores and SSD's becoming more common, many of these animations are no longer absolutely necessary, but on older systems they help tremendously for the user experience.