The billiard-ball model (BBM) is redeveloped to allow quantitative dia
grammatic evaluation of signal parameters associated with optical cohe
rent transient experiments. It is expanded to include the action of ex
ternal forces and fields as well as to include atomic-beam-type experi
ments. Matter-wave interferometric experiments are examined in the con
text of the BBM and their relationship to photon-echo experiments is e
xplored.