Design Specifications and Guidelines - Visual Design
Animation can be an effective way to communicate information. For example, it can illustrate the operation of a particular tool or reflect a particular state. It can also be used to include an element of fun in your application's interface. You can use animation effects for objects within a window and interface elements, such as icons, buttons, and pointers. However, do not use animation as the only way to convey essential information.
Effective animation involves many of the same design considerations as other graphic elements, particularly with respect to color and sound. Fluid animation requires presenting images at 16 (or more) frames per second.
When you add animation to your software, make sure that it does not affect the interactivity of the interface. Do not force the user to remain in a specific mode until the animation has finished. Unless animation is part of a process, make sure the user can interrupt it or that it is independent of the user's primary interaction.
Avoid gratuitous use of animation. When animation is used only for a decorative effect, it can distract or annoy the user. To use animation most effectively, use it for a specific purpose or condition. Avoid repeating the animation unless the condition persists or reoccurs. You should provide the user with the option of turning off the animation or otherwise customizing the animation effects.
Fundamentals of Designing User Interaction
Design Specifications and Guidelines