--- name: chart-the-truth category: data description: Make one chart that says something true. Right chart type, honest axes, labels that carry the point, exported for use. Use when they say "make a chart", "visualize this", need a graph for a class, or a chart they made looks off. --- # chart-the-truth Make one chart with someone, from their real data — the sheet from spreadsheet-basics, a tracker, survey results, team stats. One chart, done properly, teaches more than a gallery. The standard is that a stranger seeing only the chart learns something true. Use the chart tools in Google Sheets or LibreOffice Calc. ## Find the claim first A chart is a sentence in picture form. Before choosing any chart type, have them say the sentence: "spending went up after March", "most responses picked option B", "my times are getting faster". If the data does not support a sentence yet, go summarize it first (spreadsheet-basics). No sentence, no chart. ## Choose the form Match the chart to the shape of the claim, and say why out loud: - Change over time → line chart. Time on the x-axis, evenly spaced. - Comparison across categories → bar chart, sorted by value unless the categories have a natural order. - Parts of a whole → bars usually beat a pie; a pie is defensible only for two or three slices. Never a 3D pie. - Relationship between two numbers → scatter plot. One chart, one claim. If they want two claims, that is two charts. ## Make it honest These are the choices that make or break truthfulness — teach each as it comes up: - Bar charts start at zero. A truncated bar axis manufactures drama; show them the same data both ways once, so they can spot it in the wild. Line charts may zoom, but say so on the axis. - Label the axes with units. Title the chart with the claim itself ("Bus is 20 min slower than biking"), not the dataset name. - If two lines share a chart, label them directly; keep a legend only when direct labels will not fit. - Delete decoration: gridlines beyond the faintest, backgrounds, shadows, effects. Ink that is not data is noise. - A trend is not a cause. If the chart shows two things moving together, the title may say "moved together", never "because". Ask them what else changed at the same time; list rival explanations before believing the flattering one. - Few data points is a caption fact, not a secret: "n=9" belongs on the chart if only nine people answered. ## Ship it Export as PNG or SVG and put it where it was needed: the essay, the slide, the team group chat, the README of their project. A chart that never leaves the spreadsheet did not finish. Have them show it to one person cold and ask what it says — if the answer is not the claim, revise the title and labels until it is. ## Done - One chart, exported, in use somewhere real - Claim as the title, labeled axes, honest baseline, no junk - The one-sentence claim survives the cold-viewer test - They can name the dishonest version of their own chart and what it would have exaggerated Then: simple-dashboard when one chart becomes three numbers they want to keep watching.