Field Notes · 4 March 2026

Reading a side-by-side checkout poster

A walkthrough of how we annotate mobile and desktop checkout drop-offs so non-analysts can argue productively.

A checkout poster is not a dashboard. It is a single-page argument: here is where phones fall away, here is where computers continue, here is the step worth arguing about first.

Marks we always include

  • Absolute conversion from cart start to purchase for each device
  • Step-level continuation rates, not only overall rates
  • Sample size for the window, printed large enough that thin data cannot hide
  • One callout for payment method mix if it differs by device

Marks we refuse

Decorative sparklines that do not change a decision. Logo walls. Fake precision to three decimal places when the week only had a few hundred purchases.

Bring the poster to a meeting, put it on the wall, and ask which step your designers can touch this sprint. That is the whole point of the visualisation.