w3

Question 1

Dummy Variable

Answer 1

binary representation of a class of a categorical independent variable; 1 if true, otherwise 0. There should (num of classes - 1) dummy variables.

Question 2

Baseline Class

Answer 2

the class of a categorical variable represented by zero(s)

Question 3

Interpret Dummy_female having a coefficient of -105.3 on monthly insurance bill

Answer 3

“When is a person is female, their insurance bill is $105.3 less than if they were male.”

Question 4

Class

Answer 4

possible value of a categorical variable.

Question 5

Dummy Variable Trap

Answer 5

num of class = num of dummy variables; redundant.

Question 6

Quadratic Equation

Answer 6

y = B0 + B1X + B2X + e

Question 7

Piecewise step function

Answer 7

piecewise step function to predict values. Looks like stair steps. Visualize it.

Question 8

Piecewise Linear Splines

Answer 8

Have knots, each knot is a bend or change in direction of the curve, looks like lightning.

Question 9

Regression Discontinuity

Answer 9

Linear Line with a sudden jump up or down somewhere on the line; used to track the effect of a ‘“Treatment Term”