DSC 410/510 - Multivariate Statistical Methods

Assignment 17 (deadline: 4pm on Wednesday, December 1)

Practical matters

Chocolates example:

• Use SAS to reproduce the discrete choice analysis described in the class notes for the chocolates dataset (available in the "chocs.xls" spreadsheet on the data page).
• Send an e-mail to ipardoe at lcbmail.uoregon.edu with answers to the following questions:
  1. As noted in slide 9, the dark, hard chocolate with nuts is the most popular, with choice probability 0.504.
     1. Write a description of the second most popular chocolate.
     2. What is this chocolate's choice probability?
  2. Chocolate preferences could also be investigated using a traditional conjoint analysis. For example, the number of times each chocolate was chosen leads to the following ranks for chocolates 1 through 8: 6.5, 2.5, 6.5, 6.5, 2.5, 1, 4, 6.5. Running a conjoint analysis on these ranks leads to the following aggregate results:

     Attribute	Relative importance	Level	Part-worth
     dark	36.4	no	-1.000
     		yes	1.000
     soft	50.0	no	1.375
     		yes	-1.375
     nuts	13.6	no	-0.375
     		yes	0.375

     Say whether the following four statements are True or False:
     1. The discrete choice analysis and the conjoint analysis both show that the most important attribute is soft/hard followed by dark/milk followed by nuts
     2. The discrete choice analysis and the conjoint analysis both show that dark is preferred to milk, hard is preferred to soft, and nuts are preferred to no nuts
     3. In general, discrete choice analysis can be used to determine individual preferences within a sample as well as aggregate preferences, whereas conjoint analysis is restricted to finding aggregate preferences across a sample
     4. Discrete choice analysis is perhaps more realistic than traditional conjoint analysis because individuals choose just one item from those on offer rather than providing ratings/rankings for all items on offer

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

Reading

Discrete choice analysis is not covered in the text-book, so for some background reading I recommend A Brief Introduction to Discrete Choice Analysis in Marketing Research.