Does the shape of a glass play a role in determining the amount of time it takes to finish the drink? Researchers identified 159 male and female self-professed social drinkers. One week the subjects were given a 12-ounce beer with either a straight glass or a curved glass. A week later the subjects were given a 12-ounce beer in the other glass. The first week, subjects were given a glass and asked to consume the drink at their own pace while watching television. The time to complete the drink was measured. During the second week, the subjects were given the other shaped glass and asked to complete a computer task. Again, the time to complete the drink was measured. The type of glass given in the first week was determined randomly. The researchers found that the time to complete the drink was significantly faster for the curved glass.

(a) What type of experimental design is this?
(b) Who are the subjects?
(c) What is the treatment?
(d) What is the response variable? Is it qualitative or quantitative?
(e) Explain the role randomization plays in this experiment.
(f) Draw a figure that illustrates the design.