THREE FUNDAMENTAL PROBLEMS
Recall there are three fundamental problems we must solve:

• The Evaluation Problem: Given a model and a set of observations, what was the probability that the model produced these observations?
  
  
• The Decoding Problem: What was the most likely state sequence in the model that produced a given set of observations?
  
  
• The Learning Problem: Given a model and a set of observations, how can we adjust the model parameters to increase the probability of the observations (data) given the model?

In this lecture, we will focus on the third problem.