- Choosing the correct parameters whether is underfitting or overfitting

- Much harder evaluate hypothesis if we have much more features

- Split training examples, for first the usual training set.
- The second, is the test set.
- 70% for training set and 30% set for test set for the split term
- Recommended for the training set to be shuffled, or random sorted

- Inject the theta from J theta training set and implement it for theta in Jerror test
- These are the test error for linear regression
- How about logistic regression at classification?