CK-12 Probability and Statistics - Advanced

http://www.ck12.org Chapter 6. Planning and Conducting an Experiment or Study

TABLE6.3:

Subject Number Gender Age Severity

1 M 14 Mild

2 M 18 Severe

3 M 16 Moderate

4 F 16 Severe

5 F 13 Severe

6 M 17 Moderate

7 F 15 Mild

8 M 14 Severe

9 F 13 Moderate

10 F 17 Moderate

11 F 18 Mild

12 M 15 Mild

a. Identify the treatments and explain how the researcher could use blinding to improve the study.

b. Explain how you would use a completely randomized design to assign the subjects to treatment groups.

c. The researcher believes that gender and age are not significant factors, but is concerned that the original severity
of the condition may have an effect on the response to the new medication. Explain how you would assign treatment
groups while blocking for severity.

d. If the researcher chose to ignore pre-existing condition and decided that both gender and age could be important
factors, they might use a matched pairs design. Identify which subjects you would place in each of the 6 matched
pairs and provide a justification of how you made your choice.

e. Why would you avoid a repeated measures design for this study?

Answers

Multiple Choice:

1. c


2. b
   3..


3. e


4. c

Open-Ended Questions

1. Incorrect response bias. The main focus of the piece, and an issue in exit polling in general is that there is no
   guarantee that, for many possible reasons, subjects in an exit poll will answer truthfully. The pollsters also ask
   the questions in a variety of rude, unethical, and inappropriate ways that would manipulate the responses. Even
   though a real pollster would never actually engage in this type of behavior, it could be considered questionnaire
   bias.
   
   
   1. Randomly assign each tortoise a number from 1-9 using a random number generator, then incubate
      the eggs from tortoises 1-3 at 25.50 C, 4-6 at 29.50 C, and 7-9 at 33.50 C. When the tortoises hatch,
      observe and compare the ratio of female and male tortoises (which is not easy to do) at the various
      temperatures. The results of this study did confirm that the ratio of females is higher found that 29.50 C