chart-type-selectionlisted

# Chart Type Selection ## When to use Use this skill first, before you build anything. You have a table of numbers and a point to make, but you are not sure whether it should be a bar, a line, a scatter, a waterfall, or something else. Run this skill to convert "what data do I have" plus "what am I trying to say" into one defensible chart type. ## What it does It returns a single recommended chart type, a short reason tied to your message, and two runner-up options with the trade-offs. It also flags when a chart is the wrong tool and a table or a single number would land better. The output is structured so you can drop the recommendation straight into the build step. ## Method The skill runs a message-first decision tree. The driving question is never "what does the data look like" alone. It is "what is the one sentence the audience should remember, and which encoding proves that sentence fastest." Step 1. State the message in one sentence. Force the message into a single declarative claim, for example "European margin fell while volume held" or "two segments drive eighty percent of revenue." If you cannot write the sentence, stop. The chart cannot be chosen until the claim exists. Step 2. Classify the claim into one of six message types. - Comparison across categories (which is bigger, ranking). - Change over time (trend, growth, inflection). - Composition (parts of a whole, mix shift). - Relationship (correlation between two measures). - Distribution (spread, concentra