Relationships with Descriptive Data
Much of the data involved in business operations is descriptive rather than numerical. In product development and marketing we have decisions to make regarding color, shape and packaging. Surveys will have resulted in yes/no answers to questions. Records will show whether a product is popular or unpopular, whether it sells or doesn’t sell.
If the data is nominal, we speak of association between the variables rather than correlation, and this can be examined by several means. Suppose we wish to know whether a particular medical treatment is effective in helping to cure a complaint. A sample of patients might give the following results:
Yule’s coefficient ...