 James H. Martin

James H. Martin coauthored Speech and Language Processing by Daniel Jurafsky and James H. Martin with Daniel Jurafsky. Its treatment connects natural language processing to explicit probabilistic models and algorithms. The hidden-state appendix gives the initial, transition and emission distributions of a Hidden Markov model and derives the forward algorithm.^[ref]

For a sequence of observations, the forward calculation sums over possible hidden-state histories instead of selecting only one best history. Sharing partial calculations avoids enumerating every full state sequence. The resulting efficiency comes from the model's conditional-independence assumptions, not from treating arbitrary sequences as independent.