Refer to the Human Resource Management Journal (October 2008) study of workplace bullying, Exercise 12.91. Recall that multiple regression was used to model an employee's intention to leave (y) as a function of bullying (x1, measured on a quantitative scale) and perceived organizational support (measured qualitatively as "low POS," "neutral POS," or "high POS"). In Exercise 12.91b, you wrote a model for E(y) as a function of bullying and POS that hypothesizes three parallel straight lines, one for each level of POS. In Exercise 12.91c, you wrote a model for E(y) as a function of bullying and POS that hypothesizes three nonparallel straight lines, one for each level of POS.
a. Explain why the two models are nested. Which is the complete model? Which is the reduced model?
b. Give the null hypothesis for comparing the two models.
c. If you reject H0 in part b, which model do you prefer? Why?
d. If you fail to reject H0 in part b, which model do you prefer? Why?