Question

Questions 33-35. Based on the vignette below, answer the following questions.

Vignette II.  You become very interested in the large public interest in the iPhone.  You decide to use the experimental method so you can try to understand the causes of fascination with the iPhone and be able to generalize your results to the larger population beyond the Apple Store employees.  You recruit large numbers of participants, a representative sample of the larger population, and randomly assign them to treatment conditions described in the next paragraph.

You observe that much of the fascination with the iPhone is with the patented multi-touch screen. To assess the impact of this screen on participants’ desire to buy an iPhone, you randomly assign people to one of three groups.  The first group, called the “see” group, views the iPhone through a glass case, running a preloaded 30-minute demonstration that is described by the experimenter.  The second group, called the “touch” group, handles the iPhone for 30 minutes, and while they are guided through the same demonstration of features as the first group, they get to experience the multi-touch capability and move through the demonstration manually.  A third group, the “control” group, is simply given some literature about the iPhone capabilities and are allowed to review the literature for 30 minutes.  All groups are then asked how strong their interest is in buying an iPhone.  You hypothesize that participants in the “touch” group will have the strongest interest in buying the iPhone, because they were able to directly experience the screen.

33. What type of research design is described in the vignette above?

1. a single factor, two level design   
2. a single factor, multilevel design
3. a 3 x 2 factorial design
4. interrupted time series with nonequivalent control group

34. What would be the maindifficulty in interpretation of the results if each participant was first given literature, then allowed to “see” the demonstration through the glass case, and finally allowed to “touch” the iPhone and manually run the demonstration?  Note: Their desire to buy an iPhone was measured after each condition.

1. participants would get very impatient and demand to be allowed to hold the iPhone
2. differential mortality
3. the desire to buy an iPhone will be influenced by earlier experiences in your study
4. maturation

35. Any prior (before entering your study) experiences that participants might have in handling an iPhone might be considered what type of variable?

1. independent variable  
2. confounding variable  
3. dependent variable      
4. control variable

Answer 1

33. Type of research design:

Here, the researcher is interested in studying the dependent variable - Strongest interest in buying the iPhone across three treatment groups - 'See', 'Touch' and 'Control'. The factor studied here is the cause of fascination with the iPhone. Hence, the correct option would be:

1. a single factor, two level design -Here we have 3 levels of treatment, hence not correct.  
2. a single factor, multilevel design
3. a 3 x 2 factorial design - Must involve two factors with 2 and 3 levels, which is not the case here.
4. interrupted time series with nonequivalent control group - There is no time factor considered here, hence not correct.

Hence, the correct option would be: A single factor, multilevel design (3 levels)

If each participant was first given literature, then allowed to “see” the demonstration through the glass case, and finally allowed to “touch” the iPhone and manually run the demonstration and then measure their desire to buy an iPhone after each condition, one of the possibility would be, with increasing access to the features of the iphone, first by literature, then by sight and finally by touch, the desire to buy the iphone also increases. Desire scores of the first two groups might influence 'Touch' group.

Hence, the correct option would be:

c.The desire to buy an iPhone will be influenced by earlier experiences in your study

Here, in the given experiment,

Dependent variable - Strongest interest in buying the iPhone Independent variable - Type of treatment assigned  - 'See', 'Touch' and 'Control'. Control variable - variable against which the experimental groups are compared, here  “control” group, is simply the group which are given some literature about the iPhone.

Confounding variable is the that could influence the result of the experiment together with other factors variables. We test whether the factor - Type of treatment (See,Touch, Control) affects the desire to buy an iphone. But Any prior (before entering the study) experiences that participants have, is a variable that might influence, both the factors and the response (Desire to buy iphone). Hence, the correct option would be:

b. Confounding variable