Basic Analysis and Graphing - SAS

Chapter 5 Performing Oneway Analysis 145
Analysis of Means Methods
Table 5.9 Descriptions of Methods for Comparing Means
ANOM
ANOM with Transformed Ranks
Compares group means to the overall mean. This method
assumes that your data is approximately normally distributed.
See “Example of an Analysis of Means Chart” on page 162.
This is the nonparametric version of the ANOM analysis. Use
this method if your data is clearly non-normal and cannot be
transformed to normality. Compares each group mean
transformed rank to the overall mean transformed rank.
Compare Standard Deviations (or Variances)
Use the ANOM for Variances and ANOM for Variances with Levene (ADM) options to compare group
standard deviations to the root mean square error. This is a type of variance heterogeneity test.
Table 5.10 Descriptions of Methods for Comparing Standard Deviations (or Variances)
ANOM for Variances
ANOM for Variances with Levene
(ADM)
Compares group standard deviations to the root mean square
error. This method assumes that your data is approximately
normally distributed. To use this method, each group must have
at least four observations. See “Example of an Analysis of Means
for Variances Chart” on page 163.
This is the nonparametric version of the ANOM for Variances
analysis. Use this method if you suspect your data is
non-normal and cannot be transformed to normality. Compares
the group means of the absolute deviation from the median
(ADM) to the overall mean ADM.
Analysis of Means Charts
Each Analysis of Means Methods option adds a chart to the report window, that shows the following:
• a center line indicating the overall mean or root mean square error (or MSE when in variance scale)
• upper decision limits (UDL)
• lower decision limits (LDL)
If a group mean falls outside of the decision limits, then that mean is significantly different from the overall
mean. If a group standard deviation falls outside of the decision limits, then that standard deviation is
significantly different from the root mean square error.
Analysis of Means Options
Each Analysis of Means Methods option adds an Analysis of Means red triangle menu to the report window.