We have analyzed a three-mode model system to study quantum effects in a dissociative process. An algorithm which combines Hamilton's and time-dependent Schroedinger equations in an SCF manner is applied. Large differences in the qualitative behaviour of trajectories are observed which suggests a chaotic nature. The monitoring of the energy transfer or trajectories themselves by interactive computer graphics can be used to forecast possibilities of dissociation. It is also noted that the initial conditions strongly affect the dissociation process. We compare fully classical calculations with these mixed mode results, and analyze the reasons behind disparities.