2/8/2008

F-distributions: percentiles and p-value can be obtained from statistical software

Example - See catalyst.sas

Assumptions

• Normality
• Independence
• Equal standard deviations

Residual plots for checking assumptions

• Residual = observation minus estimated mean
• Plot residuals against predicted values (treatment means) and other available variables
• Construct a normal probability plot for the residuals

Multiple Comparisons

Distribution-free one-way ANOVA

• Model
• Kruskall-Wallis statistic