DSC 410/510 - Multivariate Statistical Methods

Assignment 8 (deadline: 4pm on Wednesday, October 27)

Practical matters

Illustrative Example from p502-515:

• Reproduce the analysis described in the book by working through "hatcocluster.sas" (available from the handouts page of the class web-site). This provides SAS code and instructions for running hierarchical and non-hierarchical cluster analyses 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 two questions:
  1. Tell me the % changes in the agglomeration coefficient (BSS) going from 4 to 3 clusters and going from 2 to 1 clusters for the hierarchical analysis using Ward's method in SAS (the comparable numbers in the book are in Table 9.6 on p506, but keep in mind that the book reports "within-cluster sum of squares" for the agglomeration coefficient, whereas SAS reports "between-cluster sum of squares" (BSS) so the % changes you get will be different to those in the book; however all the other results in this illustrative example should match).
  2. The non-hierarchical 2-cluster solution has significant differences between the clusters for four qualitative variables not used in the clustering procedure: X₈, X₁₁, X₁₂, and X₁₄. This helps to characterize the firms in each cluster; in particular, one cluster (labeled "1" in the text-book, but labeled "2" by SAS) might be described by which of the following:
     1. large firms engaged in modified rebuys with HATCO that primarily use specification buying in a decentralized procurement system
     2. small firms engaged in modified rebuys with HATCO that primarily use specification buying in a centralized procurement system
     3. small firms engaged in straight rebuys with HATCO that primarily use total value analysis in a decentralized procurement system
     4. large firms engaged in straight rebuys with HATCO that primarily use total value analysis in a centralized procurement system

Review questions

We may discuss some of the following questions in class on Thursday October 28. I will also provide suggested solutions to allow you to check your answers.

• Page 516: questions 4, 5, and 7.