  A statistical test is presented to decide whether data are adequately
described by probabilistic functions of finite state Markov chains (''hidden
Markov models'') as applied in the analysis of ion channel data. Particularly,
the test can be used to decide whether a system obeys the Markov condition.
Simulation studies are performed in order to investigate the sensitivity of the
proposed test against violations of the model assumptions. The test can be
applied analogously to Markov models.
