Multiple Regression

Question 1

Linear Regression involves what two variables?

Answer 1

independent variable (X) and the dependent variable (Y)

Question 2

In Linear Regression the independent variable (x) is also called the _____ variable and the dependent variable (y) is also called the _____ variable.

Answer 2

Predictor

Criterion

Question 3

What is the purpose of a multiple linear regression?

Answer 3

To determine if an outcome (dependent variable) can be predicted on the value of 2 or more known factors

In other words…analyze the relationship between metric or dichotomous independent variables and a metric dependent variable.

Question 4

The dependent variable in a multiple linear regression has to be what kind of data?

Answer 4

Metric (Ratio or Interval)

Question 5

In a multiple linear regression what kind of data can the independent variables be?

Answer 5

Nominal, Interval, or Ratio

Metric or Dichotomous

Question 6

When is multiple linear regression used?

Answer 6

In cases where the dependent variable can take any numerical value for a given set of independent variables

Question 7

When is a multiple logistic regression used?

Answer 7

in cases when the dependent variable is qualitative (dichotomous or polytomous)

Question 8

What is the purpose of a multiple logistic regression?

Answer 8

To determine what the probability of an event occurring based on the value of 2 or more known factors

Question 9

The dependent variable in a multiple logistic regression has to be what kind of data?

Answer 9

Nominal (Dichotomous)

Question 10

In a multiple logistic regression what kind of data can the independent variables be?

Answer 10

Nominal, Interval, or Ratio (Categorical or Continuous)

Question 11

Dichotomy vs. Polytomy

Answer 11

Dichotomy is a division or between two things that are opposed or entirely different

Polytomies are divisions of dichotomies into more than two secondary parts or branches

Question 12

In Multiple linear regression the dependent variable is assumed to follow what?

Answer 12

Normal Distribution

Question 13

In multiple logistic regression the dependent variable is assumed to follow what?

Answer 13

A dichotomy which means it will be only 0 or 1

Question 14

If there is a relationship between the dependent variable and the independent variables in a multiple linear regression what can we conclude?

Answer 14

Our independent variables (x1, x2, etc.) are accurate in predicting the values of our dependent variable (y)

Question 15

The more variables you use in a multiple linear regression the more _____ the model

Answer 15

Dependent

Question 16

What is the equation for a multiple regression analysis?

Answer 16

Y = α + β₁X₁ + β₂X₂

α Is our constant or our level of significance
β Is our slope

Question 17

What is the maximum number of explanatory variable allowed in a multiple regression analysis?

Answer 17

should not exceed the number of subjects ÷ 10

Question 18

What does the R² in a multiple regression analysis represent?

Answer 18

The percent of variance in y explained by the group of independent variables (X₁X₂etc.)

Question 19

So if R² = 0.9907 what does this mean?

Answer 19

This means that 99.07% of the variability in our outcome is explained by the variables in our model.

Question 20

What does ANCOVA stand for?

Answer 20

Analysis of Covariance

Question 21

What is the function of an ANCOVA?

Answer 21

To determine if there is a difference among 2 or more groups while controlling the confounding effect of extraneous factors.

Question 22

When is a ANCOVA used?

Answer 22

When the independent variable has two or more levels
AND
When there is only 1 dependent variable