ABSTRACT
The purpose of an analysis is often to compare different groups of data. Suppose, for example, that a meat scientist wants to examine the effect of three different storage conditions on the tenderness of meat. For that purpose 24 pieces of meat have been collected and allocated into three storage (or treatment) groups, each of size eight. The allocation is chosen at random. In each group all eight pieces of meat are stored under the same conditions, and after some time the tenderness of each piece of meat is measured. The main question is whether the different storage conditions affect the tenderness: Are the observed differences between the groups due to a real effect — which we would find again if we repeated the experiment — or due to random variation? And if there are differences in meat tenderness, how large are they?
