Partofspeech tagging using Hidden Markov Model solved exercise, find the probability value of the given wordtag sequence, how to find the probability of a word sequence for a POS tag sequence
POS Tagging using Hidden Markov Model  Solved Exercise
Question:
For
the given HMM, show the transition and emission probability matrices. Also,
calculate the probability of P(shePRON canNOUN runNOUN).
Solution:
As
per the HMM, the following are the transition and emission (observation)
probabilities;
Transition
probabilities

Emission
probabilities




Following
graph shows the portion of HMM to solve the given problem;
P(shePRON
canNOUN runNOUN)
= P(PRONStart) *
P(shePRON) * P(NOUNPRON) * P(canNOUN) * P(NOUNNOUN) * P(runNOUN)
= 0.4 * 0.1 * 0.001 *
0.001 * 0.1 * 0.001
= 0.000000000004
= 4*10^{12}
We
arrived at this value by multiplying the transition and emission probabilities.
**********
Go to Hidden Markov Model Formal Definition page