chart-sins/docs/content-backlog.md

# Content backlog — what to write next

Working document. The rule that generated this list: **every sin must be
condemned by something already in the canon** (`src/lib/references.ts`). We
don't invent authority, so the backlog is mined *from* the sources rather than
brainstormed and back-filled with citations.

## Canon coverage

Which references are already doing work, after the first three sins:

| Reference | Cited by |
| --- | --- |
| `callingbullshit` | truncated-y-axis |
| `clevelandmcgill` | truncated-y-axis, pie-chart-overload |
| `tufte` | truncated-y-axis |
| `howchartslie` | truncated-y-axis, dual-axis-deception |
| `datatoviz` | dual-axis-deception, pie-chart-overload |
| `spurious` | dual-axis-deception |
| `swd` | dual-axis-deception |
| `fewpies` | pie-chart-overload |
| `junkcharts` | pie-chart-overload |
| **`munzner`** | — |
| **`wilke`** | — |
| **`healy`** | — |
| **`huff`** | — |
| **`schwabish`** | — |
| **`ftvisvocab`** | — |
| **`datawrapper`** | — |

Seven idle references. Each is an authority we've already endorsed on the canon
page, so a sin that leans on one is cheap to justify and strengthens the page it
sits on. The backlog is ordered to bring them all in.

## Ranked backlog

### 1. A Cherry-Picked Time Range — *Deceptive Framing*, severity 5

**Poke:** "You started the clock exactly where the story got good."

The trend runs one way over five years and the other way over five months, so
the chart shows the five months. Nothing about the chart is technically false —
the axis starts at zero, the labels are honest — which is what makes it the
nastiest sin on this list and a good counterweight to the three scale/type sins
we already have.

**Charts:** one series, two views. Bad = the flattering slice. Fixed = the full
record with the slice shaded in place. Literally the same dataset filtered, so
the "same numbers, both charts" rule holds by construction — the strongest proof
we can build.

**Citations:** `huff` (the original con), `callingbullshit`, `howchartslie`,
`junkcharts`.

### 2. Group Averages Shown Without the Distribution — *Hiding the Data*, severity 4

**Poke:** "Four bars, four averages, and no idea whether the difference is real."

The bar-of-means: every group collapsed to one number, so wildly different
distributions draw identical bars. Wilke devotes a section to exactly this and
Healy makes the perceptual case; it's the natural home for three of our six idle
references at once.

**Charts:** bad = grouped bar of means. Fixed = strip/box plot over the same
observations, means still marked.

**Citations:** `wilke`, `healy`, `schwabish`, `datatoviz`.

### 3. Bubbles Sized by Radius Instead of Area — *Perceptual Traps*, severity 4

**Poke:** "You doubled the number and quadrupled the ink."

Scaling a circle's *radius* by the value instead of its *area* squares the
apparent difference. This is Tufte's Lie Factor with an actual number attached,
and it's the cleanest possible excuse to bring Munzner's channel ranking onto a
page — the same ranking that already underwrites the pie and truncated-axis
sins.

**Charts:** bad = radius ∝ value (a `calculate` transform squaring the size
encoding). Fixed = area ∝ value, or better, the same values as a dot plot where
position does the work.

**Citations:** `munzner`, `clevelandmcgill`, `tufte`, `howchartslie`.

### 4. Categories Sorted Alphabetically Instead of by Value — *Sloppy Craft*, severity 2

**Poke:** "Your categories are sorted by name. Nobody wants to know which
region starts with A."

Venial, universal, and the single most useful page to fire at a colleague —
which is the whole product thesis. Low severity is a feature: the gallery needs
a range, and this one brings in the FT Visual Vocabulary.

**Charts:** bad = categorical bars in alphabetical order. Fixed = same bars
sorted by value.

**Citations:** `schwabish`, `ftvisvocab`, `swd`, `fewpies`.

### 5. Stacked Segments Without a Shared Baseline — *Perceptual Traps*, severity 3

**Poke:** "Only the bottom band of a stacked chart has a straight edge to
measure against. The rest are guesses."

In a stacked column chart, every segment except the bottom one starts at a
baseline that moves from column to column, so readers can compare the total and
the bottom series — and nothing else. The series you actually care about is
usually floating somewhere in the middle. Datawrapper's guidance is blunt about
it: bring the most important value to the bottom, because readers can only
compare values that share a baseline.

Ubiquitous in business dashboards and highly sendable, which is why it outranks
the two below despite a milder severity.

**Charts:** bad = stacked columns with the interesting series stranded in the
middle. Fixed = the same numbers as small multiples (or the key series pulled
out to its own zero baseline), totals preserved.

**Citations:** `datawrapper`, `wilke`, `munzner`, `ftvisvocab`.

### 6. An Inverted Y-Axis — *Misleading Scales*, severity 5

**Poke:** "Down means up. You flipped the axis and the trend flipped with it."

The famous one. High drama, trivial to author (`scale: {reverse: true}`), and it
slots into an existing category. Ranked below the others only because the canon
support overlaps almost entirely with sins we've already published.

**Citations:** `callingbullshit`, `howchartslie`, `junkcharts`.

### 7. Aspect Ratio That Exaggerates a Trend — *Misleading Scales*, severity 3

**Poke:** "Same data, twice as tall. Aspect ratio is not a styling choice."

Cleveland's banking-to-45° argument: the identical series reads as a crisis or a
plateau depending on the box you draw it in. Cheap to author — one dataset, two
`width`/`height` pairs — and a rare sin where the bad chart contains no false
statement at all.

**Citations:** `clevelandmcgill`, `howchartslie`, `wilke`.

## Not yet buildable

Real sins, but our pipeline can't prove them honestly today. Recorded so we stop
rediscovering them:

- **3D bars / gratuitous perspective** and **chartjunk** (Tufte, Few) — Vega-Lite
  won't render the sin, and a screenshot violates the same-pipeline rule that
  makes the before/after credible.
- **Counts on a choropleth instead of rates** (Cairo's set-piece) — needs
  TopoJSON geometry and a build-time data dependency we don't have yet. Strong
  candidate the moment we take that on.
- **Rainbow color scales for continuous data** (Wilke, Munzner, and now
  Datawrapper's four-part color-scale series — the best free treatment of this
  anywhere) — the canon backing is no longer the constraint. What still blocks
  it is ours: the fixed chart needs a sequential ramp validated on
  `--chart-canvas` in both themes. Do the palette work first (`dataviz` skill +
  its validator), then this is ready to write.

## Conventions reminder

Anything picked up from this list still follows `CLAUDE.md`: the title names the
problem plainly and leaves the wit to the poke, the poke names the general sin
and never our sample's numbers, both charts share one dataset, and the fixed
chart obeys every rule the site preaches.

The headings above are working titles written to that rule — they say what the
sin *is*, so they can be taken as-is or rephrased without having to first decode
a pun.