A box-graph method for illustrating relative-size relationships in a 2×2 table

The proportional relationships of the four numbers in a 2×2 table can be displayed using two types of box graphs. In one approach, a 'unitary square' is first divided according to the denominator proportions of the two groups formed in a cohort or case-control study, and then re-divided according to the numerator proportions in each group. In the second method, the numbers are arranged as four squares, proportionately sized according to the square root of each number, and contiguously adjacent to a central reference point. The methods offer a pictorial format for showing contingency counts in a manner analogous to the graphs used for other forms of data.