When researchers are confronted with a bulk of data relating to each of a number of variables, they are faced with the task of summarizing the information that has been amassed. If large amounts of data can be summarized, it becomes possible to detect patterns and tendencies that would otherwise be obscured. It is fairly easy to detect a pattern in a variable when, say, we have data on 10 cases. But once we go beyond about 20, it becomes difficult for the eye to catch patterns and trends unless the data are treated in some way. Moreover, when we want to present our collected data to an audience, it would be extremely difficult for readers to take in the relevant information. This chapter is concerned with the various procedures that may be employed to summarize a variable.