Example Using a Supplementary Variable
This example uses the sample data on JMP employee preferences described in Example of Multiple Correspondence Analysis.
You want to explore relationships between employee job and their preferences.
1. Select Help > Sample Data Library and open Employee Taste.jmp.
2. Select Analyze > Multivariate Methods > Multiple Correspondence Analysis.
3. Select TV, Film, Art, and Resturant and click Y, Response.
4. Select Job and click Z, Supplementary Variable.
5. Click OK.
Note: Since Job is a supplementary variable, it is not used in the calculations. Job type is plotted after the calculations are complete.
Figure 7.7 MCA with Supplementary Variable Report
You can see from the plot that the data points for the R&D (research and development) and the S&M (sales and marketing) employees are close together. We interpret this to mean that there is not a strong difference in terms of preferences due to employee job function. In other words, the employee’s job role is not a significant factor in their preferences.