5.6. Case Studies
5.6.1. Eddy Current Probe Sensitivity Case Study
|Plot the Data: Ordered Data Plot||The first step in the analysis is to generate an ordered data plot.|
|Conclusions from the Ordered Data Plot||
We can make the following conclusions based on the ordered data
|Plot the Data: DOE Scatter Plot||The next step in the analysis is to generate a DOE scatter plot.|
|Conclusions from the DOE Scatter Plot||
We can make the following conclusions based on the DOE scatter
|Check for Main Effects: DOE Mean Plot||
One of the primary questions is: what are the most important
factors? The ordered data plot and the DOE scatter plot provide useful
summary plots of the data. Both of these plots indicated
that X1 is clearly important, X2 is somewhat
important, and X3 is probably not important.
The DOE mean plot shows the main effects. This provides probably the easiest to interpret indication of the important factors.
|Conclusions from the DOE Mean Plot||
The DOE mean plot (or main effects plot) reaffirms the ordering of
the DOE scatter plot, but additional information is gleaned
because the eyeball distance between the mean values gives an
approximation to the least-squares estimate of the factor
We can make the following conclusions from the DOE mean plot.
|Comparison of Plots||All of these plots are used primarily to detect the most important factors. Because it plots a summary statistic rather than the raw data, the DOE mean plot shows the main effects most clearly. However, it is still recommended to generate either the ordered data plot or the DOE scatter plot (or both). Since these plot the raw data, they can sometimes reveal features of the data that might be masked by the DOE mean plot.|