Answer to Module 1, Exercise 1o:

SS Predicted is the sum of the squared deviations of predicted scores from the mean. If the regression model is not at all useful, then the predicted score will be the mean for each case, and SS Predicted will be zero. If the regression model is only slightly helpful, then the predicted scores will be only slightly different from the mean, and SS Predicted will be small relative to SS Total. This plot would show virtually no linear relationship between X and Y, and the regression line would be close to the horizontal line for the mean of Y.


If there is a strong linear relationship in the data, SS Predicted is large relative to SS Error, and the observed data fall close to the regression line.