Misleading Chart Worksheet Generator

Four flaws, each drawn on invented data: a bar chart whose axis does not start at zero, a picture chart whose squares grow in both directions, a line chart with uneven years spaced evenly, and a pie chart whose percentages do not add up to 100. Pupils say what is wrong, how much it distorts — “the longest bar looks 2 times as long as the shortest, but the value is only 1.13 times as big” — and how to draw it fairly. The answers give the measurement and draw the fair version.

Flaws

Seed (optional)

The same seed and choice give the same charts while the generator is unchanged.

Paper size

Print size

Margin

Millimetres of blank edge, 5 to 40.

Turn the paper sideways

How to print this, or save it as a PDF

There is no PDF to download, and there does not need to be. Open the print command in your browser and choose “Save as PDF” as the destination. Your browser decides whether the page address and date print across the top and bottom; if they appear, turn off “Headers and footers” in the print dialog.
Set the scale to 100%, not “fit to page”. This sheet is already the exact size of the paper you chose, so anything that resizes it makes every measurement on it wrong.
Leave the paper size in the dialog set to the same one you chose here.

Your charts will appear here.

What this generator does

Makes two or four invented charts, each with one flaw, and answers each with what the flaw is, how much it distorts measured from the drawing, and data for a fair redraw.

How to use this tool

Choose one chart of each flaw, or two charts of one flaw.
Press Make charts, try each question, then open the answer to see the measurement and the fair chart.
Print the charts and the answer page.

Understanding the controls

Flaws: One chart of each of the four flaws, or two charts showing the same flaw for focused practice.
Paper and seed: Paper size for printing; a seed with the same choice rebuilds the same charts while the generator is unchanged.

Worked examples

One of each, seed ‘spring’: truncated bars: Books borrowed Monday to Friday, 69 to 78, axis starting at 60: the longest bar is 2 times as long as the shortest, but the value is only 1.13 times as big.
Same set: uneven years: Readers of a newsletter in 2016, 2019, 2020, 2021 and 2022 drawn evenly: the 3-year gap is squeezed into one step, so the line looks 3 times as steep there, though the rise per year is the same.
Same set: pie labels: How pupils travel to school, labelled 32, 26, 14, 7 and 15%: the labels add up to 94%. Rescaled, the shares are 34, 27.7, 14.9, 7.4 and 16%.

Common use cases

Data literacy: reading charts critically
Statistics lessons on representing data fairly
A starter before pupils draw their own charts

How this generator works

Distortion is measured between the largest and smallest values from the chart's own geometry: bar lengths above the axis start, square areas (which grow with the square of the value), or the labels' total for the pie. For uneven years, the fair redraw spaces points by the time between them, and the test checks the points then lie on one straight line, as the steady yearly rise means they must. Pie repairs rescale the labelled figures to 100% to one decimal place.

Randomness and fairness

Data are drawn with the browser's cryptographically secure generator, or from one seeded draw when a seed is typed. Seeded sheets are deterministic, not cryptographic. The measurements are computed.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

Data and topics are invented; no real organisation's figures are shown.
Each chart has exactly one deliberate flaw. Real charts can combine several, or mislead through choice of data, which these sheets do not cover.
A truncated axis is sometimes reasonable on a line chart of small changes; the sheets use bar charts, where length must match value.