Chart Selection by Argument

The argument comes first. The chart serves the argument. This is the opposite of the workflow most analysts use: find the data, decide what chart type to use for that data type, then figure out what to say about it. That workflow produces charts in search of a point. Executive charts require the reverse: decide the point, then select the chart that makes the point with maximum clarity.

Every chart in an executive deck is evidence for a specific claim. "The AI pilot outperformed the manual baseline on cost, speed, and accuracy" is a claim that requires a bar comparison or a table. "AI performance has stabilized at a level sufficient for full deployment" is a claim that requires a trend line with a threshold marker. "Our error rate is now within target range" requires a single-metric card. Match the chart to the claim, not to the data.

## ARGUMENT → CHART TYPE MAPPING

CLAIM: "We outperform the baseline."
→ Bar comparison: AI metric vs. baseline metric (2 bars)
→ Label both bars with values. Sort: higher is better on left.

CLAIM: "Performance is improving and has stabilized."
→ Trend line: 12-16 weeks, with target threshold line
→ Annotate the stabilization point. Mark the target.

CLAIM: "We are on track / off track on this KPI."
→ Single-metric card: current value, target, directional arrow
→ Red if below target. Green if at or above.

CLAIM: "Three options were evaluated. Option B is best."
→ Simple table: rows = options, columns = 3 evaluation criteria
→ Bold Option B row. Add "Recommended" label.

CLAIM: "Costs break down as follows."
→ Simple table or horizontal bar (if comparison matters)
→ Never a pie chart. Slices require mental math.

CLAIM: "We are growing faster than peers."
→ Trend line: our line + peer average line, 12 months
→ Annotate divergence point. Label both lines clearly.

RULE: If you cannot name the claim before building the chart,
you are not ready to build the chart.