01
Find the claim
Write down the conclusion the chart appears to invite. Then identify which marks or comparisons support it. A strong visual impression is not a substitute for an explicit claim.
02
Inspect the frame
Check the source, units, date range, baseline, and grouping. Ask what has been omitted. Two charts can use the same observations and produce different impressions through framing alone.
03
Try another view
Sketch an alternative scale, comparison, or ordering. You do not need a polished redesign. The exercise tests whether the conclusion survives a reasonable change of presentation.
04
Write a qualified reading
State what the chart supports and what it leaves uncertain. Keep observation separate from explanation: a visible relationship does not, by itself, tell you why that relationship exists.