Lecture 3 (End of Chapter Questions)

Question 1

What are the methods to generate attribute weights? Explain the differences between them.

Answer 1

1. Swing method: does not require knowledge of attribute value functions
2. Trade-off method: requires knowledge of attribute value functions, problematic if the attribute levels are discrete
3. Direct-ratio method: widely used but unreliable (range effect)

Question 2

What is the drawback of the direct ratio method?

Answer 2

Tries to derive weights from general statement about the importance of attributes without considering their range -> no credible result

Question 3

Explain the details of the experiment in and the findings of Fischer (1995).

Answer 3

• 45 students got divided into two groups
• Each group have the attributes starting salary and vacation days
• The range for salary is the same and the range for vacation days is different in each group
• Students were asked to assign weights to the attributes using the direct method and trade-off method

Results:

• Students were unaware of connection between range and magnitude of weights
• Direct method: difference between both groups very small
• Trade-off method: differences much larger
• Conclusion: range sensitivity increases for the trade-off method

Question 4

Explain Splitting Bias with one example.

Answer 4

• People tend to overweight an objective that is broken down into subordinate objectives when compared to an objective that is not split up
• Example: Students were asked for importance of attributes with the objective good job, individual attributes get higher values then combinations of attributes