Comparisons with Descriptive Data
Chapter 6 explained that descriptive data can be rendered numerical by expressing the numbers of items in various categories as proportions—thus enabling further analysis to be carried out on the data. In this chapter, a single proportion will be compared with a population, and two sample proportions will be compared. If the data is ordinal—that is to say, it can be listed in logical order—then ranking tests, which will be introduced, can be applied to achieve comparisons between pairs of ranks.
There is a particular advantage in having large samples of descriptive data, because several of the procedures used then allow the data to be dealt with as normally distributed ...