TheProf

TheProf t1_izh28jx wrote

To show differences, you use a line graph. To show magnitude you use a bar graph (as a general rule).

The principle of proportional ink states that sizes should be relative, meaning bar graphs should all start at zero.

If you wish to demonstrate the change in a variable, use a line graph.

Units matter as well. If zero means a lack of quantity for the variable, zero is a valid starting point. If zero does NOT represent a lack of quantity, you do not have to start at zero.

Think temperatures: zero degrees does not mean a lack of degrees. Also, we typically consider the change in temperature over time. Hence, temperatures should be represented in a line graph.

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