Chart Type Selector AI Prompt

Help me choose the right chart type for this data and communication goal.

Data description: {{data_description}}
Communication goal: {{goal}} (compare, show trend, show distribution, show composition, show relationship)
Audience: {{audience}}
Number of data points: {{n_points}}

1. Apply the chart selection framework:

   COMPARISON (how do items differ?):
   - 2–6 categories, single metric → Bar chart (horizontal preferred for long labels)
   - 2–6 categories, multiple metrics → Grouped bar or radar chart
   - Many categories, ranked → Lollipop chart or dot plot (cleaner than dense bar charts)
   - Over time with few series → Line chart
   - Over time with many series → Heatmap or small multiples

   TREND (how does a metric change over time?):
   - Single metric → Line chart
   - Multiple metrics, same scale → Multi-line chart (max 4–5 lines before it becomes unreadable)
   - Multiple metrics, different scales → Dual-axis line chart (use with caution — can mislead)
   - Showing cumulative growth → Area chart
   - Percentage change emphasis → Slope chart

   DISTRIBUTION (how are values spread?):
   - Few data points → Dot plot or strip plot
   - Many data points → Histogram or density plot
   - Comparing distributions across groups → Box plot or violin plot
   - Showing outliers prominently → Box plot with jitter overlay

   COMPOSITION (how do parts make up a whole?):
   - Few parts, single time point → Pie chart (only if ≤ 5 segments, all > 5%)
   - Few parts, prefer comparison → Stacked bar or 100% stacked bar
   - Hierarchical composition → Treemap or sunburst
   - Changing composition over time → Stacked area chart

   RELATIONSHIP (how do variables correlate?):
   - Two continuous variables → Scatter plot
   - Two continuous + third variable (size) → Bubble chart
   - Many variable pairs → Scatter plot matrix or correlation heatmap
   - Categorical vs continuous → Box plot or violin plot

2. Anti-patterns to avoid:
   - 3D charts: distort perception — never use
   - Pie charts with > 5 slices: use bar chart instead
   - Dual-axis charts with different units: often mislead — require explicit justification
   - Area charts for non-cumulative data: implies accumulation — use line chart instead

3. Recommendation:
   - Primary recommendation with rationale
   - Alternative if the primary is not available in the tool
   - One chart type to explicitly avoid for this data and why

Return: recommended chart type, alternative, anti-pattern warning, and a mockup description of what the chart should look like.