The distance between intervals (tick marks) on an axis should always be consistent with the difference in quantity that they represent. For example, equal intervals of time should be shown as equal intervals of distance in tick marks along an axis.

Each interval should still be labelled when data for the interval are missing. Indicating a break without labelling the missing intervals can be confusing and even misleading for readers (Few 2008a). Breaks in measurement or missing data should always be shown as such (eg a break in a line graph).