Graphical display in a bar chart

If we do not want to classify two categorical variables as a response and explanatory variable, the frequencies in the cells of a contingency table might be displayed as bar heights in a 3-dimensional bar chart. If bar height is defined by joint proportions instead of frequencies — the frequencies divided by the total number of individuals — the shape of the bar chart is the same.

Rank and age in a university

Three-dimensional bar charts are 'interesting' but there are more informative ways to display the data.

Chartjunk and perspective displays

Beware of adding chartjunk and perspective viewpoints to the display — they just make it harder to understand the data.