this is what we end up with and then we can do the math and find that again it comes down to Counting how about an hmm imagine some sample human hmm we see both the state X and the observation Z at all times if we have that we could estimate the model the dynamics model and the observation model again by doing counts but they were precisely we could look at the made to principally derived this we can look at these are the models we want to estimate let's look at the likelihood of this sequence of observation State and sensor observation