Hands on training Workshop Foundations of Regression Modeling

Which R package is used to clean column names in the dataset?

• car

• readxl

• janitor

• ggpubr

Which function is used to fit a linear model in R?

• predict()

• lm()

• fit.lm()

• regression()

What does the Shapiro-Wilk test assess?

• Linearity of data

• Homoscedasticity

• Normality of residuals

• Multicollinearity

What graphical method is used to check normality of residuals?

• Scatter plot

• Q-Q plot

• Boxplot

• Heatmap

What is the purpose of Cook’s Distance?

• To check correlation

• To measure prediction accuracy

• To detect influential observations

• To estimate multicollinearity

What threshold is used to identify influential points using Cook’s Distance?

• 1

• 0.5

• 4/n

• R² value

Which metric is not part of the get_model_metrics function?

• R-squared

• Adjusted R-squared

• RMSE

• VIF

What does the ncvTest() function check in a regression model?

• Normality of data

• Variance inflation

• Non-constant variance (heteroscedasticity)

• Influential observations

What does the vif() function check for?

• Independence of observations

• Homoscedasticity

• Multicollinearity

• Outliers

In which plot are predicted and observed values compared visually?

• Q-Q plot

• Histogram

• Predicted vs Observed plot

• Residual vs Fitted plot