What are the four rules for using Venn diagrams to encourage higher order thinking?

Here are the four rules for using the Venn Diagram for higher order thinking

1. The Venn diagrams are used for both classification and comparisons. Don't limit to only one of them.

2. Venn diagrams don't have to be circles.

3. You need to draw the universal set.

4. Venn diagrams don't have to be very simple. It's okay to complicate the Venn diagrams in order to capture the classifications and the comparisons.