Significance Tests in Multiple Regression (1 of 2)
The following formula is used to test whether an R²
calculated in a sample is
significantly
different from zero. (The
null hypothesis
is that the population R² is zero.)
where N is the number of subjects, k is the number of predictor variables
and R² is the squared multiple correlation coefficient. The
F is based on k and N - k - 1
degrees of freedom.
In the
example of predicting college
GPA, N = 100, k = 3, and R² = .3997.
Therefore,
In addition to testing R² for significance, it is possible
to test the individual regression
coefficients for significance. This is done by dividing the
regression coefficient by the
standard
error of the regression coefficient.