Simple and Multiple Linear Regression

Question 1

Correlation

Answer 1

quantify the strength of association between two variables (one of which must be at least interval): r ranges between -1 and 1

determine the direction of the assocation (positive or negative)

test for statistical significance (e.g., whether r  0) and you can construct a confidence interval around r

calculate partial and semi-partial correlations to eliminate the influence of third variables

Question 2

Linear Regression

Answer 2

goes beyond correlation, allows you to make predictions

Question 3

R2

Answer 3

The proportion of variance of the outcome variable explained by the model, relative to the total variance of the outcome variable. Assesses how well the model fits the data