Accuracy is the ubiquitous goal of dynamic simulation, in order to yield the "correct"
motion. But for creating animations, what is really of interest is "plausible"
motion, which is somewhat different. We discuss what we mean by plausible
simulation, how it differs from "accurate" simulation, and why we think
it's a worthwhile area to study. The discussion touches on questions of
physically plausible vs. visually plausible motion, plausible simulation in
a noisy or textured environment, and probability measures for motion, as
well as issues for forward and inverse problems.