Orthogonal Regression

Graphs - Residuals versus Fits

This graph plots the residuals versus the fitted values. The residuals should be scattered randomly about zero. Use this plot to look for the following:

This pattern...	Indicates...
Fanning or uneven spreading of residuals across fitted values	Nonconstant variance
A point far away from zero	An outlier
A point far away from the other points in the x-direction	An influential point

Example Output

Interpretation

For the glucose data, the residuals appear to be randomly scattered about zero. Evidence of nonconstant variance, outliers, or influential points does not exist.