Use protected t tests for the data in Exercise 16.7 or 16.9 to clarify the meaning of the significant F.

Exercise 16.7

Foa, Rothbaum, Riggs, and Murdock (1991) conducted a study evaluating four different types of therapy for rape victims. The Stress Inoculation Therapy (SIT) group received instructions on coping with stress. The Prolonged Exposure (PE) group went over the events in their minds repeatedly. Those in the Supportive Counseling (SC) group were taught a general problem solving technique. Finally, the Waiting List (WL) control group received no therapy. Data with the same characteristics as theirs follow, where the dependent variable was the severity rating of a series of symptoms.

Exercise 16.9

Use the R code on this chapter’s Web page to generate data that could lie behind exercise 16.7 and then run the analysis of variance.

Transcribed Image Text:

Group n Mean S. D. SIT 14 11.07 3.95 PE 10 15.40 11.12 SC 11 18.09 7.13 WL 10 19.50 7.11