A+ Answers

1. The table below shows ratings of various aspects of work and home life of 100 middle-class men in India who were fathers. Pick three rows of interest to you and explain the results to someone who is familiar with the mean, variance, and Z scores, but knows nothing else about statistics.

 Comparison of Fathers' Mean Psychological States in the Job and Home Spheres (N = 100)

2 Barker and colleagues (2012) compared 61 parents of children who had a serious mental illness (SMI) to 321 parents of children without such an illness. The researchers examined the parents’ reported levels of stress, their levels of a hormone called cortisol (levels of this hormone provide an indication of chronic stress), and their use of several types of medication. The table below shows the results of the study. Focusing on the parents’ number of stressors (the first row of the table) and the parents’ use of medications for anxiety or depression (the last row in the table), explain these results to a person who knows about the t test for a single sample but is unfamiliar with the t test for independent means.

3. For each of the following studies, say whether you would use a t test for dependent means or a t test for independent means.

4. An experiment is conducted in which 60 participants each fill out a personality test, but not according to the way the participants see themselves. Instead, 15 are randomly assigned to fill it out according to the way they think their mothers see them (that is, the way they think their mothers would fill it out to describe the participants); 15 as their fathers would fill it out for them; 15 as their best friends would fill it out for them; 15 as the professors they know best would fill it out for them. The main results appear in Table 9-17. Explain these results to a person who has never had a course in statistics.

5. Rosalie Friend (2001), and educational psychologist, compared three methods of teaching writing. Students were randomly assigned to three different experimental conditions involving different methods of writing a summary. At the end of the two days of instructions, participants wrote a summary. One of the ways it was scored was the percentage of specific details of information it included from the original material. Here is a selection from her article describing one of the findings: