 One of the measures used to detect chaotic behavior in classical systems is a positive Kolmogorov entropy, which can be related to Lyapunov exponents (e.g., Atmanspacher and Scheingraber 1987). Unfortunately, there are no appropriate analogous for Lyapunov exponents in quantum systems. There are alternative entropy measures that could be used, for instance, the von Neumann or Connes-Narnhofer-Thirring entropies. However, there are currently many open questions about which, if any, of these entropy measures is the appropriate quantum analog (likely they are each appropriate for particular research purposes). Moreover, while these measures have a relationship to the statistics of energy levels and states characteristic of quantum chaology, there currently are no other known features of quantum systems that these measures could relate to chaotic behavior observed in classical trajectories. 