Summary

In this paper, the author identifies that user interfaces of the time
were confusing (particularly to new users) because of sudden changes.
The system would transition from one state to another without
providing the user with any connection between those two states. The
author asserts that principles of animation can be applied to the user
interface to smooth these transitions making the connection between
successive states easier to interpret for the user.

Problem

User interfaces use static presentation causing objects to
appear/disappear, move, or otherwise change without any indication as
to the transition or how an object in the previous state relates to an
object in the current state.

Methods Used

Principles of animation such as solidity, slow-in/slow-out,
anticipation, exaggeration, follow through, etc. are used to make a
more lively, more believable user interface.

Key Ideas/Contributions

1. Principles of animation can be applied to user interfaces to make
them more realistic, more engaging, and more lively.

Questions/Flaws

This issue was raised by the authors, but I believe it bears
mentioning. The use of animation in the user interface can hinder
one's ability to use the interface (after they have adapted to using
it). For example, in Windows, minimizing a window causes it to
instantaneously disappear. On Mac OS X the window is "sucked" in to
the dock using a "genie" animation. While the animation on OS X is
quick and relatively unobtrusive, it does take time. That is time that
I could spend working with the applications behind the minimized
window. Basically, I believe that sometimes animation can get in the
way of the user interface unless great care is taken, though
interfaces do need to progress and better convey the illusions of
solidity and consistency.