Dec 10, 2008

Hidden Markov Model, Maximum Entropy Hidden Markov Model and Conditional Random Field

Thanks Peng Xu for teaching me about these three models. The differences between them are as follows:
  1. HMM: arrow from st-1 to st, and from st to ot
  2. Maximum Entropy HMM: arrow from st-1 to st, but from ot to st
  3. CRF: no arrow between st-1 and st, neither between st and ot
References:
  1. Andrew Mccallum, Dayne Freitag, Fernando Pereira. Maximum entropy Markov models for information extraction and segmentation, ICML 2000.

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