The ladder

You read the chart.
Then you read what it left out.

One question, asked harder at every rung. Four rungs, 20 dives, every chart drawn from public data you can go and check. Each rung asks what a shape leaves out, and asks it of harder shapes. Nothing here needs a network.

Dive in → 1.1Every value, and no shape

01what’s thereread one 02what’s reportedread one and name the gap 03what’s relatedjudge two 04what isn’t theretest a claim

20 dives · four rungs

rung 1 · shallow

what’s there

read one

Question one at this rungWhat kind of chart is this, and what is one thing it cannot show you?

The rung 1 plan →

1.1Every value, and no shapeThe table is the plainest way to hold data, and it fails at a size you can feel.the table · the bar · civic15 min 1.2A ranking of places, a ranking of sizesThe same shape, handed two things that could not be more different.the bar · civic20 min 1.3A number with no comparisonTwo stages, and the order is the lesson.the number · the bar · civic20 min 1.4The icon is a unit, and it breaksTwo ways a picture graph falls apart -- at the top of one file and the bottom of another.the picture graph · the bar · civic25 min 1.5Two ways a donut failsSlices too close to rank, and one slice that swallows the rest.the donut · the bar · civic20 min1.MMake one: students build the chartTwenty minutes in the pool, not five. Not written yet; left on the ladder so it stays planned.20 min

no dive at this rung matches

rung 2 · deeper

what’s reported

read one and name the gap

Question one at this rungWhat was actually measured, and when was it recorded?

The rung 2 plan →

2.1Complaints, and the catalogueTwo datasets that are not about what their names say.the bar · the line · civic30 min 2.2Two instruments that are not independentThe obvious way to check a proxy, and why it does not work.the bar · civic30 min 2.3A pattern with a mechanism, and one withoutSimilar sizes. Completely different shapes.the bar · civic20 min 2.4The day Los Angeles went quietThe hole and the spike are the same event, and neither of them is people.the histogram · the line · civic25-40 min 2.5The smoothest line in scienceWhat a measurement looks like when almost nothing is wrong with it.the line · civic15 min2.MMake one: students build the chartTwenty minutes in the pool, not five. Not written yet; left on the ladder so it stays planned.20 min

no dive at this rung matches

rung 3 · deep

what’s related

judge two

Question one at this rungWhere does this series start and end, and who chose that?

The rung 3 plan →

3.1The window decides the answerOne series. One hundred and thirty-two honest answers.the line · civic30 min 3.2A mean is a deletionShown with something they already know was deleted.the bar · the box plot · civic20 min 3.3A real correlation and a nonsense oneA hundredth of a point apart.the scatter · civic25 min 3.4Change the bin, move the clusterNot one data point changes.the hexagonal binning map · the dot density map · earth and space20 min 3.5A choropleth spends its ink on landAnd land does not breathe.the choropleth map · the bar · earth and space20 min 3.6One measure is not a profileTwo adults describe the same students and disagree about who is struggling. Both of them are right about their own measure.parallel coordinates · civic30 min3.MMake one: students build the chartTwenty minutes in the pool, not five. Not written yet; left on the ladder so it stays planned.20 min

no dive at this rung matches

rung 4 · the bottom

what isn’t there

test a claim

Question one at this rungDoes the evidence reach the claim?

The rung 4 plan →

4.1These counties have clean airA claim to test. It fails.the choropleth map · the bar · earth and space25 min 4.2Every region is warmingTrue of the planet. False of a band containing an ocean.small multiples · civic25 min 4.3Earthquakes are decliningStand in 2022 and it looks true.is this real, or noise? · the bar · civic25 min 4.4Earth-like planets are rareThe largest question a person can ask, answered by an instrument.the scatter · the scatterplot matrix · civic30 min4.MMake one: students build the chartTwenty minutes in the pool, not five. Not written yet; left on the ladder so it stays planned.20 min

no dive at this rung matches

The strand

1 — Read the Chart

What does this chart actually say?

2 — What the Number Counts

Is the thing measured the thing named?

3 — The Shape of the Picture

Would a different chart change the answer?

4 — The Map Is a Chart

What geography adds to the ways a chart fails.

5 — Find Your Own

Can you source a number you will defend?

6 — Make One That Lies

Mislead with only true numbers, then say so.

Protocol — Full Cycle

The five steps, aimed at any dataset.

The shapes we teach

is this real, or noise?parallel coordinatessmall multiplesthe barthe box plotthe choropleth mapthe donutthe dot density mapthe hexagonal binning mapthe histogramthe linethe numberthe picture graphthe scatterthe scatterplot matrixthe table

16 shapes, quoted from the library. The 12 in lighter type do not yet say what they leave out. That is an open question, not a hidden one, and a class can answer it.

All thirty shapes, drawn

Reference

Why this is here

Not a math class: the field's own position, and what provenance is for.

The Data Dive bank

A five-minute warm-up that ladders.

Two datasets per shape

One that affects them, one Earth and space.

Rung 1 — What's There

Five built dives, ready to run.

Rung 2 — What's Reported

The proxy rung. Five built dives.