Honest baseline bars zero or truncation

honest-baseline-bars-zero-or-truncation

Honest baseline: bars start at zero or show truncation. Meaningful scales, consistent time intervals, readable labels. Don’t rotate labels to hide a truncated axis.

Description

Honest baseline: bars start at zero or show truncation. Use meaningful scales, consistent time intervals, and readable labels. Don’t rotate labels to hide a truncated axis. Pass when bars start at zero or truncation is shown, scales and intervals are consistent, and labels are not rotated to hide truncation. Fail when a truncated bar axis has no truncation mark or labels are rotated to hide it.

When to use

Bar charts where baseline and scale honesty matter.

Not when

Truncated bar axes without a mark, or labels rotated to hide truncation.

Agent hint

Start bars at zero or mark truncation; never rotate labels to hide a truncated axis.

Pass

Bars start at zero, or truncation is shown; scales/intervals are consistent; labels are not rotated to hide a truncated axis.

Fail

Truncated bar axis with no truncation mark; labels rotated to hide it.

Citations

NSW — Charts and graphs

https://designsystem.nsw.gov.au/docs/content/methods/charts-and-graphs.html