Partial Least Squares

Residual Analysis Plots - Residuals versus Fits

This graph plots the standardized 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
Curvilinear	A missing higher-order term
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

$image\plsr_14n.gif$

$image\plsr_15n.gif$

Interpretation

Based on these plots, the residuals appear to be randomly scattered about zero, indicating linear relationships and constant variance in the data, although evidence of outliers exists. Brushing the graph identifies points that may be outliers.

· The plot for moisture indicates that soybean samples 22 and 36 may be outliers. Both observations were outliers on the distance plot.

· The plot for fat shows that the soybean sample 39 may be an outlier.