Dr. Zak Case Study
Read the following case study. Use the information in the case study to answer the accompanying follow-up questions. Although questions 1 & 2 have short answers, you should prepare a 150- to 200-word response for each of the remaining questions.
Dr. Zak developed a test to measure depression. He sampled 100 university students to take his five item test. The group of students was comprised of 30 men and 70 women. In this group, four persons were African American, six persons were Hispanic, and one person was Asian. Zak’s Miraculous Test of Depression is printed below:
1. I feel depressed: Yes No
2. I have been sad for the last two weeks: Yes No
3. I have seen changes in my eating and sleeping: Yes No
4. I don’t feel that life is going to get better: Yes No
5. I feel happy most of the day: Yes No
Yes = 1; No = 0
The mean on this test is 3.5 with a standard deviation of .5.
1. Sally scores 1.5 on this test. How many standard deviations is Sally from the mean? (Show your calculations)
2. Billy scores 5. What is his standard score?
3. What scale of measurement is Dr. Zak using? Do you think Dr. Zak’s choice of scaling is appropriate? Why or why not? What are your suggestions?