Introduction to Multiple Regression (1 of 3)
In multiple regression, more than one variable is used to
predict the criterion. For example, a college admissions
officer wishing to predict the future grades of college
applicants might use three variables (High School GPA, SAT,
and Quality of letters of recommendation) to predict college
GPA. The applicants with the highest predicted college GPA
would be admitted. The prediction method would be developed
based on students already attending college and then used on
subsequent classes. Predicted scores from multiple
regression are
linear
combinations of the predictor variables. Therefore, the
general form of a prediction equation from multiple
regression is:
Y' = b
1X
1 +
b
2X
2 + ... +
b
kX
k + A
where Y' is the predicted score, X
1 is the score on the first
predictor variable, X
2 is the score on the second, etc. The
Y intercept is A. The regression
coefficients (b
1, b
2, etc.) are analogous to
the
slope in
simple
regression.