At run time, a dimension is filled with categories. The number of categories can be an indication to:
- Present a different type of graph;
- Decide to use replacement instead of insertion of the categories of the level below;
- Split the categories automatically into smaller groups.
If the number of categories exceeds the limit of 6, a pie chart would be inappropriate (
Zelazny, 1996) or the rest of the categories should taken together in a single group
‘Other...’. Moreover, pie charts cannot be used if among the categories there are positive as well as negative numbers. In that case, a bar chart is a better choice.
