Let’s summarize what we’ve discussed so far in a comparison table:
| Overfitting | Underfitting |
|---|---|
| Model is too complex | Model is not complex enough |
| Accurate for training set | Not accurate for training set |
| Not accurate for validation set | Not accurate for validation set |
| Need to reduce complexity | Need to increase complexity |
| Reduce number of features | Increase number of features |
| Apply regularization | Reduce regularization |
| Reduce training | Increase training |
| Add training examples | Add training examples |