Question 7
After training a linear regression model on a large training set of size
, it achieves a training
error of
. Analysis of the residual plot shows a clear non-linear pattern, suggesting the model is underfitting the data. Which two of the following modifications are most likely to improve the model’s performance by increasing its capacity to capture non-linear relationships?
Adding a regularization term (such as L2 or L1 penalty) to the mean squared error loss function.
Using a 2-hidden layer feedforward network with ReLU activation functions in place of linear regression.
Applying a polynomial feature transformation of degree
to the input variables.Standardizing all training samples to have mean zero and unit variance.
Using a 5-hidden layer feedforward network without non-linear activation functions in place of linear regression.