# Sources & authentic provenance

This skill is an original synthesis of widely taught information-design principles. It quotes nothing and reproduces no spreads. Where a principle has a clear authentic origin, that origin is listed below — cite these, never this skill, when the lineage matters. Preserving these sources matters: the distillation is deliberately narrow, and the primary texts go far deeper.

## Primary inspiration — the book and its author

- **David McCandless, _Information is Beautiful_**, William Collins (HarperCollins), London. First edition 2009, ISBN 978-0007294664; new edition 2012 ("thoroughly revised, recalculated and reimagined"), 256 pp., ISBN 978-0007492893. Published in the US as _The Visual Miscellaneum: A Colorful Guide to the World's Most Consequential Trivia_ (Harper Design, 2009, ISBN 978-0061748363). The skill's entire posture — form follows data, beauty as a means of comprehension, data as landscape — is a response to this atlas. Bibliographic record: https://openlibrary.org/books/OL44136188M/Information_Is_Beautiful
- **informationisbeautiful.net** — the author's site and the blog the book grew from; hundreds of free visualizations with open datasets, constantly revised. https://informationisbeautiful.net
- **TEDGlobal 2010 (Oxford, July 2010), "The beauty of data visualization"** — the public statement of the philosophy this skill encodes (infographics as "knowledge compression"; data as "the new soil"). https://www.ted.com/talks/david_mccandless_the_beauty_of_data_visualization
- **davidmccandless.com** — the author's portfolio; sequels _Knowledge is Beautiful_ (2014) and _Beautiful News_ (2022). https://davidmccandless.com
- **Legal access routes:** the publisher (HarperCollins), bookshops, public libraries via WorldCat, Open Library controlled lending, Google Books preview.

## Classic lineage the synthesis also draws on

The five laws synthesize doctrines taught publicly for decades by the wider field — this skill claims no ownership of them:

- **Edward Tufte**, _The Visual Display of Quantitative Information_ (1983). Origin of the data-ink ratio, chartjunk, and small-multiples vocabulary — this skill's Law IV ("ink must be earned") is Tufte's maxim restated, and his name belongs on it.
- **Stephen Few**, _Show Me the Numbers_ (2004/2012) and _Now You See It_ (2009). Perceptual ranking of encodings (position > length > angle) and much of `chart-matcher.md`'s pragmatism derive from Few's analytical-communication practice.
- **Alberto Cairo**, _The Functional Art_ (2012). The balance this skill demands between beauty and honesty owes its framing to Cairo's functional-art argument.
- **William S. Cleveland & Robert McGill** — perceptual ranking of encodings (position > length > angle/slope > area).
- **Jacques Bertin**, _Sémiologie graphique_ (1967) — retinal variables and their information.
- **Cynthia Brewer** — ColorBrewer: sequential/diverging/qualitative schemes and colourblind-safety testing.
- **WCAG 2.x (W3C)** — the contrast thresholds (≥ 3:1 graphical marks, ≥ 4.5:1 small text) and the "never colour alone" rule are accessibility standards, not from the book — credited here because passing them off as book wisdom would be false provenance.

## Named spreads referenced as public concepts

Chart titles such as the "Billion-Dollar-o-Gram", "Snake Oil Supplements", "Mountains out of Molehills", "Colours in Culture", and "Left vs Right" are named here only as **publicly known concepts** to point the agent at the authentic, richer originals. The originals — artwork, layout, and data — are © David McCandless; study them at informationisbeautiful.net or in the book.

## Skill-section → source map

- Law I (form follows data) + three reading depths → McCandless (book/TED/site), Few.
- Law II (honest scales) + failure modes → Tufte, Few, Cairo.
- Law III (colour as a channel) + `palettes.md` → Few/Cairo + the book's "Colours in Culture" lesson that hue carries culture-dependent meaning.
- Law IV (earned ink) → Tufte.
- Law V (annotation as narration) → McCandless + Cairo.
- Accessibility floor → WCAG 2.x.
- Cultural-colour caution → the book's Colours-in-Culture spread (concept only).

## What this skill does NOT contain

- No text, figures, layouts, or datasets from the book.
- No reproduction of any spread (the "Billion-Dollar-Gram" idea, for instance, is referenced by name and concept, never redrawn).
- Nothing here is affiliated with, or endorsed by, David McCandless or HarperCollins. It is a fan-made homage, licensed MIT for remixing.

## Format source

- The **Agent Skills open specification**: agentskills.io/specification — required `name` + `description` frontmatter, optional `license`, `compatibility`, `metadata`, `allowed-tools`; companion docs under `references/` loaded on demand (progressive disclosure).
- Client-specific behaviour (slash-command invocation, personal vs project scopes, plugin marketplaces): Claude Code documentation, code.claude.com/docs/en/skills.