How to present data in a presentation

Across the thirty four finished decks on this site there are three hundred and sixty four slides, and fifteen of them carry a chart. Four per cent. The quarterly business review deck, the one built specifically to report numbers to a board, has exactly one chart in ten slides. That ratio is not an accident of authoring. Most claims about data are better made in a sentence, a table or a single large number, and the chart is for the claims that are genuinely about shape.

Claim first, chart second

Write the claim as a sentence before you open the chart editor. “Churn is worse in the accounts we onboarded before March” is a claim. “Churn by cohort” is a topic, and a topic produces a chart that the room has to interpret for itself.

Once you have the sentence, the chart follows from the kind of relationship it asserts. Stephen Few reduced this to seven quantitative message types in 2004: nominal comparison, time series, ranking, part to whole, deviation, frequency distribution and correlation. Each has a small set of encodings that work. Time series wants lines to show the pattern or bars to emphasise the individual values, with time always on the horizontal axis. Ranking wants bars, sorted descending to highlight the top and ascending to highlight the bottom. Deviation wants a reference line, always.

The Financial Times Visual Vocabulary, made by its visual journalism team, does the same job with nine categories rather than seven and a wider chart list underneath each: deviation, correlation, ranking, distribution, change over time, part to whole, magnitude, spatial and flow. Either sheet works. What matters is that you pick the category before the picture.

Ten charts and their claims

The table under this article lists the ten chart kinds a slide can hold and what each is good and bad at. Two practical notes about how they appear in the builder.

First, a chart that arrives as part of a layout offers only the kinds that layout allows, which is three or four across every chart bearing template. A chart dropped in from the element library carries all ten. If the kind you want is missing from the switcher, that is why.

Second, the waffle is the only one of the ten with no native PowerPoint equivalent, so it exports as a picture while the other nine become real charts. That is worth knowing before you build a board pack that somebody else will edit.

Headlines as findings

The slide title is the claim. “Q3 revenue” is a filing label. “New revenue beat plan by nine per cent while gross churn ran 1.6 points over it” is a finding, and a reader who sees only the title has still received the message.

The quarterly review deck does this from the cover onwards: the verdict in five words, growth held, churn did not, before any number appears. Its scorecard carries a status column that says ahead or behind on every row, so the reading takes two seconds rather than twenty. Its before and after slide has a change column, which is the whole point of showing before and after.

A useful test: cover the chart with your hand. If the title still tells you what happened, it is a finding.

Labels on the data, not in a legend

A legend makes the reader hold a colour in their head, look back at the chart, and match it. That is a small tax paid on every glance, and in a room where the chart is on screen for ninety seconds it is not small.

Put the label next to the thing it names. The donut on slide eight of the partnership proposal deck sets each percentage beside the thing it pays for. Where a line chart has two series, name them at the right hand end of each line rather than in a box below. Where a bar chart has one series, the categories are already labelled on the axis and the legend is pure decoration.

Colour: one series highlighted

Amy Esselman’s advice on colour is the shortest useful rule I know: “Color should be an explicit choice, not something your software applies by default.” She recommends starting in greyscale, which “gives you a neutral foundation and serves as a reminder that more work needs to be done”, then colouring only what needs emphasis. In her worked example, colouring just the negative values tells the audience exactly where to look.

On a slide this means one series carries the theme colour and everything else is grey. The colour mode itself is set per slide here, cycling through spectrum, matching, outline and dark, so a chart that reads well on a white slide can be switched without rebuilding it. What no colour mode can fix is five series all shouting at once.

Tables when the reader needs the numbers

Charts answer questions about shape. Tables answer questions about values. If somebody in the room will say “what was it in March”, you need a table, and pretending otherwise means they will ask anyway and you will squint at a line chart together.

Twenty seven of the three hundred and sixty four example slides carry a table, which is nearly twice as many as carry a chart. A table slot grows to twenty rows and eight columns, with an optional first column as a row header, which is more than any slide should ever use. Seven rows is a scorecard. Twenty rows is an appendix.

The other reason to prefer a table is that it survives being read alone. As Amy Esselman puts it, a deck asked to be a live presentation, a pre-read and a reference at once ends up serving none of them properly, and the chart is usually the first casualty.

The example: a quarterly review with four data slides

The quarterly business review deck has ten slides and four of them are data. Slide two is a seven row scorecard with target, actual, variance and status, three rows marked behind. Slide three is the deck’s only chart, new recurring revenue against churned revenue by month on one pair of lines. Slide four is six measures for cohorts before and after an onboarding rebuild, with a change column. Slide five is the pipeline as four falling numbers, from four hundred and eighty six qualified opportunities to a hundred and eight live and paying, which is a funnel that needed no chart at all.

For what a chart slide can hold and how the data is entered, see chart slides; for what survives the trip into PowerPoint, the editable export page lists it. And if these slides are going into a first meeting, where they sit in a sales deck matters as much as how they are drawn.