Lung Disease, Indigestion, and Two-way Tables

This paper considers the responses of 115 school students to two problems based on information provided in two-way tables. In each case the question asks if one of the variables involved depends on the other. Contextual knowledge might suggest a dependent relationship in both but in one problem the data show independence while in the other the data imply an inverse relationship. A wide range of solution strategies illustrates the cognitive complexity dealing with information in two-way tables.