Timeline encodes values as position along an ordered time axis. Joseph Priestley’s 1765 Chart of Biography inspired later atlases.
In reports, ads and assignments it fits ordered events, eras, project milestones. Skip it when you need quantities changing, not just dates.
Principles
- Encoding — Timeline encodes position along an ordered time axis.
- History — Joseph Priestley’s 1765 Chart of Biography inspired later atlases
- Fit — ordered events, eras, project milestones
- Shared baseline — The eye compares length and position more accurately than area.
- Audience — PowerPoint, Excel or Google Sheets and Meta, Google and retail print share the same geometry.
Misconceptions
- Pretty equals true — Decoration rarely persuades; it slows reading.
- 3-D helps — Perspective distortion wrecks comparison. Keep it flat.
- More series is richer — Do not stack stories. One Timeline, one claim.
- Default palette is fine — Rainbow defaults fail color-blind viewers and grey print. Change Excel or Google Sheets defaults.
Why it matters
- Work — Work: ordered events, eras, project milestones. Readable in four minutes in PowerPoint.
- Ads — Ads: one number and one shape speak first in Meta, Google and retail print.
- School — School: for lab reports and poster boards, pick the form that answers the rubric.
- Craft — Craft: honour position along an ordered time axis and decoration falls away.
Timeline: honour position along an ordered time axis, and switch when you need quantities changing, not just dates.