Scenario 9 – Perception of Fabric Softness
Fabric softeners are conditioners that are applied to laundry during a washing machine rinse cycle and have the effect of making the laundry "feel" softer. You have been hired as a consultant scientist to evaluate the effect of different concentrations of fabric softeners on this subjective feeling of softness and whether it differs between men and women. Your experimental design utilises the magnitude estimation method as developed by Stevens where participants rate the softness of clothes following washing in different concentrations of softener. You have four samples of clothes that were washed with different concentrations of softener, and participants can rate them using a simple scale (1-10; where 1=Not Soft, 10=Most Soft). You collected the following data based on testing a small group of individuals:
Fabric softener concentration (ml/L) | 250 | 300 | 400 | 600 |
---|---|---|---|---|
Intensity Ratings - Females - |
1.2 | 2.1 | 4.0 | 6.4 |
Intensity Ratings - Males - |
2.2 | 3.9 | 6.3 | 9.6 |
On the same graph, plot the psychophysical functions for softness intensity for both males and females.
Which group is more sensitive to the fabric softener? Explain your reasoning.
If you were interested in finding a rough estimate of the absolute detection thresholds of fabric softener in a wash, explain how you might achieve this based on your data. Based on your proposed approach, which group would have the lower threshold?