Regression Wisdom

Question 1

Extrapolation

Answer 1

Doing this: predicting values of x far from the ones used to find the linear model equation, with linear regression should not be trusted.

Question 2

Outliers in linear regression…

Answer 2

Watch for these cases that (1) have a large residual and/or (2) have high leverage.

Question 3

Leverage

Answer 3

Data points whose x-values are far from the mean of x exert this on a linear model.

Question 4

Influential point

Answer 4

A point that, if omitted from the data, results in a very different regression model.

Question 5

Lurking Variable

Answer 5

A variable that is not explicitly part of the model but affects the way the variables in the model appear to be related.