Question

1. The Food and Drug Administration (FDA) wants to determine which fast food burger joint will make individuals gain the most weight. The FDA gathers 150 volunteers and decides to evenly and randomly allocate them to eat one burger a day at either Wendy’s, McDonald’s, or Burger King for a month. After that one month, FDA will calculate each individual’s weight change.                                                                 

1. Identify the “subjects” of this experiment.   
2. Identify the treatment(s).
3. Outline the design of this experiment
4. What is a potential lurking variable in this experiment?   

Answer 1

a) The subjects of the experiment are 150 volunteers.

b) The treatment is eating one burger a day at either Wendy's, Mcdonald's or Burger King (3 treatments in total)

c) The design of the experiment is randomization as the volunteers are randomly allocated across the three treatment groups, which means that 50 volunteers each are randomly selected from the sample size of 150 volunteers who eat one burger a day at Wendy's, Mcdonald's and Burger King.

d) One of the potential lurking variable could be the physical activity of the volunteers which is not controlled for the same. As each volunteer might have a different intensity of physical activity everyday which can impact the weight gain of the volunteer. Hence, this is a potential lurking variable which could affect the relationship between two variables.