ISYE 6501 Final Questions and Answers 2025 Update 100% Correct.

ISYE 6414 Final / ISYE 6501 Final | Questions

and Answers | 2025 Update | 100% Correct.


1. If there are variables that need to be used to control the bias selection in the model, they

should forced to be in the model and not being part of the variable selection process. -

CORRECT ANSWER True

2. Penalization in linear regression models means penalizing for complex models, that is, models

with a large number of predictors. - CORRECT ANSWER True

3. Elastic net regression uses both penalties of the ridge and lasso regression and hence combines

the benefits of both. - CORRECT ANSWER True

4. Variable selection can be applied to regression problems when the number of pre- dicting

variables is larger than the number of observations. - CORRECT ANSWER True

5. The lasso regression performs well under multicollineariy. - CORRECT ANSWER False

6. The selected variables using best subset regression are the best ones in explaining and

predicting the response variables. - CORRECT ANSWER False

, 8. The lasso regression requires a numerical algorithm to minimize the penalized sum of least

squares. - CORRECT ANSWER True

9. An unbiased estimator of the prediction risk is the training risk. - CORRECT ANSWER

False

10. Backward and forward stepwise regression will generally provide different sets of selected

variables when p, the number of predicting variables, is large. - CORRECT ANSWER True

11. All regularized regression approaches can be used for variable selection. - CORRECT

ANSWER False

12. Before performing regularized regression, we need to standardize or rescale the pre- dicting

variables. - CORRECT ANSWER True

13. The larger the number of predicting variables is, the larger the bias but the smaller the

variance is. - CORRECT ANSWER False

14. Variable selection is a simple and solved statistical problem since we can implement it using

the R statistical software. - CORRECT ANSWER False

15. BIC penalizes for complexity of the model more than AIC or Mallow's Cp statistics. -

CORRECT ANSWER True

16. The penalty constant λ in penalized or regularized regression controls the trade-off between

lack of fit and model complexity. - CORRECT ANSWER True

17. We cannot perform variable selection based on the statistical significance of the regression

coefficients. - CORRECT ANSWER True