MOSAIC PLOTS (AND BAR GRAPHS)

A mosaic plot shows the frequencies in an n-way table by nested rectangular regions whose area is proportional to the frequency in a cell or marginal subtable. The display uses color and shading to represent the sign and magnitude of standardized residuals from a specified model.

Comparison of Mosaic Plots and Bar Graphs
A mosaic plot presents the same information as is presented by a stacked bar-graph: The frequencies of combinations of categories of two variables.
1.A mosaic plot consists of rectangles laid out in a mosaic. The rectangles are like the sub-bars in a stacked bar-graph.
2.In a mosaic plot, each column of rectangles represents a category of the variable on the horizontal axis.
3.In a stacked bar-graph, each bar represents the overall frequency of a category of the variable plotted on the horizontal axis. In a mosaic, the several column of tiles are all the same height, representing 100%. Thus each tile in a mosaic represents a proportional frequency of a category combination.
4.Whereas a stacked bar-graph's sub-bars representing the joint frequency of a category of each of the two variables, in a mosaic plot each rectangle represents the joint probability of a category of each of the two variables. 