Categorical data from several groups

Useful information can sometimes be obtained by examining a single categorical distribution with a bar or pie chart. However more interesting questions can usually be asked of data when they are obtained from several groups.

Rice survey

The data may not be presented as separate lists of values from each group. The groups may equivalently be defined by a categorical variable in the original data matrix. Each 'individual' again contributes a count of 1 to a single cell of the contingency table.

Rice survey