... for HMM Hidden Markov Models Ankur JainY7073• Define the backward variable βk(i) as the joint probability of the partial observation sequence ok+1 ok+2 oK given that the hidden state ... Covered•Observable Markov Model• Hidden Markov Model•Evaluation problem•Decoding Problem• Set of states: • Process moves from one state to another generating a sequence of states : • Markov chain ... states at each instant of time Markov Models },,,{21 Nsss ,,,,21 ikiisss)|(),,,|(1121 −−=ikikikiiikssPssssP )|(jiijssPa =)(iisP=π• By Markov chain property, probability...