Due Day 7: 4/1/13: Dr. Zak Case Study This is a team assignment, so make sure every participant’s name is on the assignment. Please have one member post in the “ Assignments” link. Then, upload your Certificate of Originality to the Assignments link. You may answer questions on this form; you do not have to format in this form (also attached); you do not have to format into a paper. You do not need to upload a plagiarism report for this assignment. Dr. Zak Case Study Instructions Read the following case study.
Then, 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 to each of the remaining questions. Case Study 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: YesNo 3. I have seen changes in my eating and sleeping: YesNo 4. I don’t feel that life is going to get better: YesNo 5. I feel happy most of the day: YesNo Yes = 1; No = 0 The mean on this test is 3. 5 with a standard deviation of . 5. Follow-Up Questions 1. Sally scores 1. 5 on this test. How many standard deviations is Sally from the mean? Show your calculations and answer in a complete sentence. ) 2. Billy scores 5. What is his standard score? (Show your calculations and answer in a complete sentence. ) 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? 4. Do you think Dr. Zak has a good sample on which to norm his test? Why or why not? What are your suggestions? 5. What other items do you think need to be included in Dr. Zak’s domain sampling? . Suggest changes to this test to make it better. For each suggestion justify your reason supporting each reason with psychometric principles from the text book or other materials used in your course. 7. Dr. Zak also gave his students the Beck Depression Inventory (BDI). The correlation between his test and the BDI was r =. 14. Evaluate this correlation. What does this correlation tell us about the relationship between these two instruments? What does it tell us about Dr. Zak’s test?