Insomnia and education. Refer to the Journal of Abnormal Psychology (Feb. 2005) study of whether insomnia is related to education status, presented in Exercise 1.30

(p. 50). A random-digit telephone dialing procedure was employed to collect data on 575 study participants. In addition to insomnia status (normal sleeper or chronic insomnia), LO4 the researchers classified each participant into one of four education categories (college graduate, some college, high school graduate, and high school dropout). One dependent variable of interest to the researchers was a quantitative measure of daytime functioning called the Fatigue Severity Scale (FSS). The data were analyzed as a 2 * 4 factorial experiment, with Insomnia status and Education level as the two factors.

a. Determine the number of treatments for this study. List them.

b. The researchers reported that “the Insomnia *
Education interaction was not statistically significant.”
Interpret this result practically. (Illustrate with a graph.)

c. The researchers discovered that the sample mean FSS for people with insomnia was greater than the sample mean FSS for normal sleepers and that this difference was statistically significant. Interpret this result practically.

d. The researchers reported that the main effect of Education was statistically significant. Interpret this result practically.

e. Refer to part

d. In a follow-up analysis, the sample mean FSS values for the four Education levels were compared with the use of Tukey’s method (a = .05), with the results shown in the accompanying table. What do you conclude?
Mean: 3.3 3.6 3.7 4.2 Education: College graduate Some college High school graduate High school dropout