| name | data-viz |
| description | Design, choose, and critique data visualizations. Use when picking chart types (line, bar, dot, scatter, histogram, heatmap, map), reviewing fit/integrity, polishing editorial or interactive charts, or applying Tufte principles: graphical integrity, data-ink, chartjunk, small multiples. Use apple-design for in-app chart UX/accessibility. Triggers: chart type, dashboard design, data visualization, chartjunk, data-ink, small multiples, D3 tooltip. |
Data Visualization
Defaults that survive without the references:
- Single important number → stat callout, not a chart; exact lookup → table.
- Time trend → line chart; dash the segment for projections or incomplete periods.
- Category magnitude → bars from a meaningful zero; zero not informative → dot plot/lollipop.
- Never dual y-axes or pie/donut for fine comparison; prefer indexed lines or small multiples.
- Prefer direct labels near marks over legends; the main point must read at mobile width without interaction.
Read the reference that matches the task:
- Choosing a chart (which type fits the data and question; building dashboards, reports, decks, frontend visuals): references/chart-selection.md; deep dive: chart-decision-matrix (full prefer/use-when/avoid-when table)
- Critiquing or redesigning (graphical integrity, data-ink ratio, chartjunk, small multiples, dense displays, visual encodings): references/tufte.md; deep dives: tufte-principles (critique vocabulary), analytical-design (sparklines, layering, dense dashboards)
- Editorial and interactive chart craft (NYT/Upshot-style chart pages, dashboard polish, direct labels, annotations, hover hit testing, tooltip behavior, mobile prepublish checks): references/editorial-interaction.md
- Sources and gaps — provenance map and parked candidate standards: references/sources.md, references/coverage-gaps.md
Typical flow: select the type first (chart-selection), refine integrity/density with the critique principles (tufte), then use editorial-interaction when the chart must ship as a polished page, dashboard, or interactive artifact. For the in-app experience around a chart — platters, progressive disclosure, Swift Charts, Audio Graphs, accessibility labels — use apple-design (chart-experience-design) instead.
