Read the following case study. Use the information in the case study to answer the accompanying follow-up questions. 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:
Yes = 1; No = 0
The mean on this test is 3.5 with a standard deviation of .5.
- Do you think Dr. Zak has a good sample on which to norm his test? Why or why not? What are your suggestions?
- Suggest changes to this test to make it better. Justify your reason for each suggestion supporting each reason with psychometric principles from the text book or other materials used in your course.
- 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 you about the relationship between these two instruments?