DSC 410/510 - Multivariate Statistical Methods

Assignment 10 (deadline: 4pm on Wednesday, November 3)

Practical matters

Two-group Illustrative Example from p281-296:

• Reproduce the analysis described in the book by working through "hatco2group.sas" (available from the handouts page of the class web-site). This provides SAS code and instructions for running a discriminant analysis on the hatco data (available in the "hatco.xls" spreadsheet on the data page).
• Send an e-mail to ipardoe at lcbmail.uoregon.edu with answers to the following questions:
  1. SAS computes the classification results in Tables 5.10-11 using the "posterior probability" method rather than the "cutting score" method (see class notes slide 27). In this example, this results in a slightly different classification matrix for the analysis sample, and hence a different prediction accuracy. What is the SAS hit ratio prediction accuracy (see slide 29) for the analysis sample (i.e. in the book, the hit ratio prediction accuracy for the analysis sample is (21+34)/60 = 91.7% - what is the comparable calculation based on the SAS results)?
  2. Which of the following statements provides the best interpretation of the results. (Hint: magnitudes of discriminant function loadings give an indication of the variables that are most important for discriminating between the groups, with positive loadings associated with the group that tends to have positive values on the discriminant function and negative loadings associated with the group that tends to have negative values on the discriminant function. SAS only provides the loadings for variables used in the analysis - the Excel spreadsheet on the data page calculates the loadings for all the variables available; these are also in Table 5.13 on page 294).
     1. firms following total value analysis have higher perceptions of Hatco on product quality and price level, whereas specification buyers are more favorable on delivery speed and price flexibility
     2. firms following total value analysis have higher perceptions of Hatco on delivery speed and price flexibility, whereas specification buyers are more favorable on product quality and price level
     3. firms following total value analysis have higher perceptions of Hatco on price level and price flexibility, whereas specification buyers are more favorable on product quality and delivery speed
     4. firms following total value analysis have higher perceptions of Hatco on product quality and delivery speed, whereas specification buyers are more favorable on price level and price flexibility

This assignment is worth 15 points rather than the usual 10.