Applied Research Methods

Review attached case study and answer questions.

The Case of the Dieters

A young college professor was driving down the road one day and heard the radio announcer
describe an amazing new product. “Simply drink this new diet fuel at bedtime” the announcer said “and
you will lose pounds and inches as you sleep! You can eat whatever you want, our amazing diet fuel
will burn it off!”.

“Wow,” the professor thought, “that’s got to be a rip-off. I can’t believe that people are trying
to sell junk like that to the public. If only someone could prove them wrong!”. After mulling it over for
a couple of minutes, an idea came to her. Maybe there was a way to prove them wrong and maybe
she was the one to do it!

As she continued to think, an idea for an experiment came to her. In it, she would identify a
group of 10 overweight people. She would instruct them to eat whatever they wanted but to be sure to
drink the new diet fuel, which she would supply, every night for the next two weeks. At the end of the
two weeks she would weigh them again. Obviously, she thought, if the group weighed the same or
significantly more than they did prior to the two week trial period, the product was a farce. After
thinking through her plan for a couple of minutes, the professor decided to go for it. Nothing would suit
her better than to prove these scam artists wrong!

1. What is the hypothesis that the professor is investigating?

2. What is the independent variable? What are the levels of the independent variables?

3. What is the dependent variable?

4. Which statistical test would the professor use to test her hypothesis?

5. For each of the sets of output below, what can you tell about the dependent variable? What
decision would the professor make?

Case A:

Variable Group Number Mean Standard Standard Error
of Pairs Deviation of the Mean

Weight Before 223.3 45.7361 14.4630

After 224.6 46.7813 14.7935
10

Mean of the t Degrees 1-tailed 2-tailed
Paired Differences value of p value p value

Freedom

Pair 1 Before 1.30 2.053 9 ..035 .070
After

Case B:

Variable Group Number Mean Standard Standard Error
of Pairs Deviation of the Mean
Weight Before 223.3 45.7361 14.4630

After 221.1 45.8729 14.5063
10

Mean of the t Degrees 1-tailed 2-tailed
Paired Differences value of p value p value
Freedom

Pair 1 Before -2.20 -2.051 9 .0355 .0710
After

Case C:

Variable Group Number Mean Standard Standard Error
of Pairs Deviation of the Mean
Weight Before 223.3 45.7361 14.4630

After 221.9 45.3663 14.3461
10

Mean of the t Degrees 1-tailed 2-tailed
Paired Differences value of p value p value
Freedom

Pair 1 Before -1.40 -1.326 9 .109 .218
After