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Data Storytelling: A Free Guide With Examples for Reports and Slides

Public reports and handbooks explained in plain language, and an Academy that teaches the craft behind them.

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Now showing · 22 briefings · 12 lessons · 4 lab pieces

Listen · AF Measuring Guidelines Handbook

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Circumference in inches, plus height in feet, plus a quarter of the average crown spread in feet.

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Circumference in inches, plus height in feet, plus a quarter of the average crown spread in feet. That single sum is how American Forests scores a champion tree, and it comes straight out of a technical handbook written mainly by two veteran tree measurers, Bob Leverett and Don Bertolette, working with a small group of state and national coordinators between about two thousand twelve and two thousand fifteen. The handbook organizes its rules by skill level, from beginners just starting to measure trees up to a national cadre of expert measurers, and it is precise almost to a fault. Circumference is taken at four and a half feet above the ground, the forestry standard known as diameter at breast height. If the trunk leans, the tape goes on at ninety degrees to the lean, not parallel to the ground. On sloping ground, there is a specific mid slope rule: find the point where the seed likely first fell, and measure up from there. Six separate diagrams cover different trunk shapes, from a single straight trunk to trees that fork low or fuse together, each with its own measurement rule. Height gets three older stick methods, a traditional tangent method, and what the handbook itself calls the preferred method: the sine method, which uses trigonometry rather than simple angle estimation, and which the handbook argues is far less error prone. Crown spread is measured with an axis method or a spoke method, taking the widest diameter of the canopy and its perpendicular, then averaging the two. Put a hypothetical tree through the formula and the logic becomes concrete. Take a large white oak, two hundred inches around, a hundred feet tall, with an average crown spread of sixty feet. Two hundred plus one hundred plus fifteen, a quarter of sixty, comes to three hundred fifteen points. That is not a real recorded tree; it is simply the arithmetic worked through, the same way the handbook itself walks a reader through it. The program the handbook serves traces back to nineteen forty, to a magazine article called "Let's Find and Save the Biggest Trees," and its first nominated tree was a chestnut oak in Suffield, Connecticut. The handbook describes itself as a living document, expected to be revised again, not a fixed, permanent standard.

Every briefing and every lesson comes with a narrated version. Open the full briefing

A slide projector throws a bar chart with one highlighted bar onto a screen

Data storytelling is the work of turning a spreadsheet, a report or a set of survey results into something a reader can actually follow: a finding, a cause, and a next step, carried by the right chart instead of buried under one that only looks impressive. A number on its own rarely sticks. A number with a cause attached to it, shown in a chart chosen for the job rather than for familiarity, almost always does. The data storytelling examples below come from real public reports, and every one of them can be opened and checked.

What data storytelling actually is

The habit splits into two separate skills that usually get taught as one. The first is choosing and drawing a chart honestly: picking the type that matches what the data is for, comparison, change over time, distribution, a relationship between two things, and drawing it without a cut axis, a cherry-picked date range or a 3D tilt distorting what the numbers actually say. The second is structure: organising a finding around a setup that states what was normal, a tension that names what changed, and a resolution that says what should happen next, the same shape a story has always had, applied to a dataset instead of a plot.

Public reports and handbooks are a good place to watch both skills in practice, because their authors were solving the same problem long before “data storytelling” became a phrase anyone used deliberately. The National Patient Safety Agency’s 2008 risk matrix compresses a genuinely hard judgement, how serious is this risk, into a five-by-five grid a member of staff without risk-management training can read correctly in seconds. The American Forests measuring guidelines do something similar with a formula instead of a grid: circumference plus height plus a quarter of crown spread, a single number that turns three separate field measurements into one comparable score. Neither document calls itself a data storytelling guide, but both are doing exactly what one teaches.

A data storytelling guide in three steps

The practical version of this data storytelling guide compresses down to three moves, applied in order. Start with the sentence the data needs to prove, not the chart, since most bad charts are really a symptom of skipping this step: “region three grew fastest” or “churn fell after the onboarding change” already names its own chart type before a single pixel gets drawn. Then pick the chart built for that sentence’s purpose, covered in full in the which chart should I use guide, or answered directly by the chart chooser tool in a few clicks. Finally, check the chart for the honesty traps that undo good chart selection anyway: a truncated axis, a cherry-picked range, a legend sitting too far from the lines it explains.

That third step matters as much as the first two, and it is the one skipped most often under deadline pressure. A perfectly chosen chart type, drawn with a cut axis, still misleads a reader just as effectively as the wrong chart type would have. Reading reports critically depends on the same instinct in reverse: knowing what to check before trusting a chart someone else built, which is the subject of its own full guide to reading a report elsewhere on this site.

Data storytelling examples from real documents

Some of the clearest data storytelling examples come from documents built to be used under pressure, not admired on a shelf. The European Athletics Championships Statistics Handbook is compiled edition after edition by a Finnish statistics firm specifically so a journalist mid-broadcast can confirm, in seconds, whether a result just set inside the stadium beats a record set decades earlier by an athlete from a different generation entirely. That is not a chart at all; it is a sorted, indexed table, because the actual reader need was precise lookup, not a picture of a trend. Choosing a table over a chart, deliberately, is itself a data storytelling decision.

A different kind of example comes from Adobe’s 2015 consumer research, which reported that a majority of surveyed consumers abandon content that runs too long, and a similarly large share stop reading over poor design alone. The finding is itself an argument for the discipline this guide describes: a report or a slide that buries its point under six charts and no throughline is asking for exactly the kind of patience that research found in short supply, even a decade ago. Structure is not decoration; it is the difference between a finding that gets remembered and one that gets skimmed past.

Practising the skills, not just reading about them

Reading a chart-selection rule is not the same as building the instinct to apply it under a real deadline, which is why every lesson in the Academy pairs its guidance with something to try directly: a chart chooser tool that recommends a chart type from two or three questions, a game that hands over twelve real questions already paired with a chart and asks which pairings actually hold up, a slider that blurs three slide designs to show which one still reads its message from across a room. The Lab collects all of these short, ungated exercises in one place, each built to be finished in a few minutes without an account or a download.

None of this replaces judgement, and none of it claims data storytelling reduces to a formula that removes the need for it. What a genuinely useful data storytelling guide can do is name the recurring mistakes early enough that they get caught before a chart ships, and name the recurring structure clearly enough that a finding, once found, actually survives the trip from a spreadsheet to a reader’s memory.

Two tracks, built to be used separately or together

The Academy runs as two short tracks rather than one long course. The first covers charts and slides directly: picking the right chart type, spotting the handful of tricks that make an honest chart look dishonest or a dishonest one look fine, structuring a slide so a message survives contact with a real audience. The second covers reading and building reports: where a document’s actual argument usually sits, what an executive summary is supposed to do that an introduction isn’t, what a margin of error actually claims and what it doesn’t. Either track stands on its own, and a reader who only ever needs to fix one recurring problem, a report that gets skimmed past or a chart that keeps landing wrong, can start on the lesson that matches it directly rather than working through the whole sequence first.

The public documents used as examples throughout both tracks are chosen the same way: for what they show about a real decision under real constraints, not for polish. A risk matrix built by a health authority that closed over a decade ago and a measuring formula built for foresters comparing trees across different states have nothing obviously in common with a quarterly sales deck, and that is exactly the point. The underlying moves, compress a judgement into something scannable, state a formula precisely, choose a table over a chart when a table actually serves the reader better, repeat constantly across fields that never call what they’re doing “data storytelling” at all. Naming the pattern once tends to make it easier to recognise the next time it shows up somewhere unrelated.

Questions

What is data storytelling?

Data storytelling is presenting numbers so that a reader can follow them: a clear finding, the context or cause behind it, and a chart chosen to show exactly that point. It combines two skills, drawing an honest chart of the right type and structuring the finding like a short story with a setup, a change and a consequence.

Are the briefings, lessons and games free?

Yes. Every briefing, Academy lesson, explainer and Lab game can be used without an account, a subscription or a download. Games keep their scores only in the browser that plays them.

Where do the documents in the briefings come from?

They are public reports, handbooks, standards, court filings and studies published by government bodies, universities, professional associations and companies. Each briefing names the publisher and the year, and links to the original wherever the publisher still offers it.

How are the audio briefings made?

Each briefing and lesson has a written narration script that is read by a synthetic voice. The transcript under the player is that exact script, so the audio and the text always say the same thing, and clicking a sentence in the transcript jumps the audio to it.

Where should a beginner start?

The chart chooser answers the most common question, which chart fits a given point, in under a minute. From there the lesson on reading a report and one of the briefings as a worked example cover the other half: getting the finding out of a long document before trying to present it.

Tray B

Academy

Lessons on charts, slides and reports. Each one has a narrated walk-through, an interactive piece and a short check.

  1. Slot C-01Which Chart Should I Use?Which chart should I use for this data? A practical guide to chart types by purpose, with real chart type examples and a tool that recommends one for you.
  2. Slot C-02Chart Chooser ToolThe chart chooser tool asks a few questions and recommends a chart, with the reasoning and traps spelled out, plus a cheat sheet you can scan on its own.
  3. Slot C-03Spot a Misleading GraphHow to spot a misleading graph: truncated axes, missing legends and 3D distortion, with real examples and a short checklist to run before trusting any chart.
  4. Slot C-04Tell a Story With DataHow to tell a story with data, for beginners: a setup, tension and resolution framework with real examples, so a chart-filled report becomes memorable.
  5. Slot C-05Slide Design ChecklistA slide design checklist built from two named rules, the 6x6 rule and the 10-20-30 rule, with examples of what each one catches and what it doesn't.
  6. Slot C-06Assertion-Evidence SlidesAssertion-evidence slides replace a topic phrase and bullets with a full-sentence headline and one piece of visual evidence, backed by Penn State research.
  7. Slot R-01How to Read a ReportHow to read a report quickly: a guide to report structure, section by section, with claims-versus-evidence notes and two real reports read start to finish.
  8. Slot R-02How to Read an Annual ReportHow to read an annual report for beginners: every section explained, from a 10-K's numbered items to the UK strategic report and a non-financial example.
  9. Slot R-03Executive Summary ExamplesAn executive summary example for a report, a simple template, and how executive summary vs introduction actually differ, with a padded example rewritten short.
  10. Slot R-04Margin of Error ExplainedMargin of error explained simply, with real numbers: why ±3.1 points needs 1,000 people, why a poll's lead needs double that margin, and what it cannot see.
  11. Slot R-05Document Design and ReadabilityDocument design principles that actually improve readability: contrast, repetition, alignment and proximity, why white space matters, and a short checklist.
  12. Slot R-06Accessible PDF ChecklistAn accessible PDF checklist explained: what tagging does, the PDF/UA and WCAG standards behind it, how to test with a screen reader, and the common failures.