Chapter 10 FAQ: Hidden Markov Models
Questions learners ask most about Chapter 10, Why Have Biologists Still Not Developed an HIV Vaccine?
Chapter 10 is in the print book and the interactive course. Its lecture videos are free.
Since a deletion state does not emit a symbol, why is it not the case that all emission probabilities in a deletion state are zero?
It may seem that all edges entering into deletion states in the Viterbi graph should have weight zero. However, for purposes of the Viterbi graph, deletion states can be thought of as emitting a blank symbol ("-") with probability 1.