## Number of HMM states

**How many HMM states are there?**

**Not known**

Not too many people know that a hidden Markov model (HMM) is a statistical Markov model in which the system being modeled is assumed to be a Markov process with hidden states. It is interesting to know that the state is directly visible to the observer, and therefore the state transition probabilities are the only parameters. Needless to say, each state has a probability distribution over the possible output tokens. Be aware of the fact that the adjective ‘hidden’ refers to the state sequence through which the model passes, not to the parameters of the model.

This fact is verified on : December 6, 2013.