This section describes concepts and techniques for
validating control algorithms and for conveying linguistic and
para-linguistic information by facial animation. By validation, we
mean an evaluation of the degree to which synthetic faces mimic the
behavior of real faces. To date, there is a considerable body of
prior work that has been aimed at evaluating of the auditory
communication channel. This section therefore describes some of this
body of prior work.
Basically, there are two general approaches that can be employed: