Description

This chapter begins with a linear-model analysis where the aim is to compare the effects of different treatments. Each treatment is applied to a group of experimental units and, if the treatments are effective, they will produce differences between the groups. Experiments are designed to test hypotheses about the effects of the treatments and to quantify the strength of these effects. This chapter focuses on describing the treatment effects (a step we often skimp on in our haste to get to the punchline), saving testing for later.