ISYE 6414 Final Exam – Part 1 Solutions | All Answers are Correct

Final Exam – Part 1 Solutions 1. We should always use mean squared error to determine the best value of lambda in lasso regression. a. True b. False Sol: False. The criterion used is a choice we make. 2. Standard linear regression is an example of a generalized linear model where the response is normally distributed and the link is the identity function. a. True b. False Sol: True. See Unit 4.4.1. 3. Goodness-of-fit assessment for logistic regression involves checking for the independence, constant variance, and normality of the deviance residuals. a. True b. False Sol: False. We don’t have constant variance in binomial regression. 4. You are interested in understanding the relationship between stress level and exercise, with stress as the response. In your model, the number of hours a person spends exercising per week would be considered an explanatory variable while the person’s age would be a controlling variable. a. True b. False Sol: True. Time spent exercising is part of the relationship you are trying to understand while age could act as a confounding variable that you need to control. 5. The hypothesis test for goodness-of-fit using Pearson residuals and the test using deviance residuals will always reach the same conclusion. a. True b. False Sol: False. One test may conclude plausibly good fit while the other rejects it. 6. A logistic regression model with high goodness of fit can have low predictive power. a. True b. False Sol: True. See Unit 4.2.3