Question 7.63
33. Stores advertise price reductions to attract customers. What type of price cut is most attractive? Market researchers prepared ads for athletic shoes announcing different levels of discounts (20%, 40%, or 60%). The student subjects who read the ads were also given “inside information” about the fraction of shoes on sale (50% or 100%). Each subject then rated the attractiveness of the sale on a scale of 1 to 7.
- Each treatment in this experiment is a combination of values of two explanatory variables: discount level and fraction on sale. List all the treatments.
- Outline a randomized comparative experiment using 60 student subjects. Use Table 7.1 (page 298) at line 123 to choose the subjects for the first treatment.
33.
(a) There are six treatments, each combination of a level of discount and fraction on sale. In table form, the treatments are as follows:
| Discount Level | |||
| 20% | 40% | 60% | |
| 50% on sale | 1 | 2 | 3 |
| 100% on sale | 4 | 5 | 6 |
The six treatments are as follows (enumerated for ease of reading):
Treatment 1: 20% off shoes; 50% of shoes on sale
Treatment 2: 40% off shoes; 50% of shoes on sale
Treatment 3: 60% off shoes; 50% of shoes on sale
Treatment 4: 20% off shoes; 100% of shoes on sale
Treatment 5: 40% off shoes; 100% of shoes on sale
Treatment 6: 60% off shoes; 100% of shoes on sale
(b) The outline randomly assigns 10 students to each of the 6 treatment groups, then compares the attractiveness ratings. It resembles Figure 7.3, but with 6 branches.
Label the subjects 01 to 60 and read line 123 of Table 7.1 (page 298). The first group contains subjects labeled 54, 58, 08, 15, 07, 27, 10, 25, 60, and 55. In order, these are 7, 8, 10, 15, 25, 27, 54, 55, 58, and 60.