Homework 2 - Due Thursday, Feb 14

1. An experimenter was interested in whether the gender of a person effects the way that they carry books (hugged to the chest or held down by the hip). To test this he observed both males and females walking through campus and recorded which way they carried their books. He found that females tend to hug books to their chest while males hold them at their hip.

Question 1: What is the Dependent Variable in this experiment?

Question 2: What is the scale of the Dependent Variable (nominal, ordinal, interval, ratio)?

Question 3: What is the Independent Variable of the experiment?

Question 4: Is the IV a manipulated or subject variable (explain why)?

Question 5: What can we conclude from this study about why the two genders carry their books differently?

The experimenter also things that the weight of the books carried could effect the method of holding the books. He brings participants into the lab and tells them that they will be filling out a survey on creativity. Before filling out the survey he pretends to be clearing a spot away on a table for the participant and asks them to briefly hold a single book. He varies for different participants whether the book is very light (4 lbs), or heavy (18 lbs). He asks them to walk across the room with the book and place it on a shelf. He records the way in which each participant holds the book, and then tells them the actual purpose of the study. There were an equal number of men and women in each group. His results showed that the heavier book was generally held at the chest, while the light book was carried at the hip.

Question 1: Is the IV a situational, task, or instructional variable? (explain why)

Question 2: What can we conclude from this study about why the two books were carried differently?

 

2. Another researcher is interested if people would be more likely to buy a food product with fewer food additives than a similarly priced one with more additives. He sets up an experiment as a local grocery store. Every third customer who enters the market is stopped and asked to participate in a study of consumer preferences. The researcher shows the participant two containers of potato chips. The first container labeled "crunchy chips" (in bright, cheerful colors) lists the following ingredients: potatoes, oil, & salt. The second container labeled "sludgy chips" (in dull, unattractive colors) lists these ingredients: potatoes, oil, salt, monosodium glutamate, calcium silicate, disodium inosinate, disodium guanylate polymorphosperversinate, artifical flavor, and artificial color. Both packages had a price tag of $3.50. He then asks the participant to examine both packages and indicate the one they would be more likely to buy. His IV is number of food additives and his DV is which product the particpant chooses.

His results showed that 232 out of 236 shoppers selected the first product as the one they would purchase. The researcher concluded that people are more likely to purchase a product with fewer food additives, if the price is shown to be the same.

Question 1: This experiment contains two confounding variables. Identify each confound separately and explain how each alone could have caused the results.

Question 2: Explain how you could have fixed this study so that it was free from confounds?