ABSTRACT
Chapter 22 discussed methods for analyzing data for balanced and unbalanced mixed models. This chapter presents detailed analyses using examples for each situation. The data for the unbalanced case is obtained by randomly deleting some observations from the data for the balanced situation. The study involved a company wanting to replace machines used to make a certain component in one of its factories. Three different brands of machines were available, so the management designed an experiment to evaluate the productivity of the three machines when operated by the company’s own personnel. Six employees (persons) were randomly selected from the population of employees that are trained to operate such machines. Each selected employee was required to operate each machine during three different shifts. The data recorded were overall productivity scores that took into account the number and quality of components produced. The data are given in Table 23.1.
