Montgomery’s Textbook "Design and Analysis of Experiments"
Posted by hank in Uncategorized on February 2, 2006
Example 8-6. After using a log transformation Montgomery examines the normal probabilty plot of the residuals and says: “This plot is suggestive of slightly heavier than normal tails, so possibly other transformations should be considered.”
The Box-Cox plot for Montgomery’s model (A, B, AD) suggests an inverse transform which seems to clear up all the residual plots and clarify the model. Give it try.