Presenting a data story

Why it matters

Analysts are often judged less by the quality of their analysis than by whether anyone acts on it. A correct finding buried on slide 14 changes nothing. A data story is a short, structured presentation that takes the audience from a question to a recommendation, with just enough evidence to trust it. It is not about drama or spin; it is about respecting the audience's time.

Find the one message first

Before you open any slide software, finish this sentence in no more than two lines:

"We should [action] because [evidence], which will [benefit]."

For example: "We should add a delivery-time estimate to the checkout page because 38% of abandoned carts happen on the shipping step, and the stores that tested it recovered about a fifth of those carts."

Nancy Duarte and Cole Nussbaumer Knaflic both recommend this "big idea" step. If you cannot write it, your analysis is not finished, or you are trying to say too many things.

A three-slide structure

For a short update (five minutes or less) three slides is enough:

Slide 1: Context and question. What situation are we in, and what question did we ask? Include one number that shows why it matters. "Checkout completion fell from 64% to 58% this quarter. We looked at where customers drop off."

Slide 2: The key evidence. One chart, decluttered, with a takeaway title that states the finding. "Most drop-off happens at the shipping step." Highlight the bar or line that proves the point. Put supporting detail in an appendix, not on this slide.

Slide 3: Recommendation and next step. The action, its expected impact (with a range if uncertain), what it costs, the caveats, and the decision you need from the audience. "Recommend: show delivery estimates at checkout. Expected: recover 15% to 25% of shipping-step drop-offs. Caveat: based on a two-week test in three stores. Decision needed today: approve a four-week A/B test."

This follows a classic arc: setup, conflict, resolution. It also follows the "answer first" pyramid principle: busy readers who only see slide 3 still get the message.

Make each slide readable

• Headline = the takeaway, written as a full sentence.
• One chart per slide, sized large enough to read from the back of the room.
• Highlight with colour, grey the rest (Module 1).
• Annotate: add a short label directly on the chart at the point that matters ("Shipping step: 38% of drop-offs").
• Numbers rounded to what the decision needs: "38%", not "37.86%".
• Speak to the chart, do not read it. Say what to look at, then why it matters.

Know your audience

• Executives want the answer, the impact and the decision needed. Lead with slide 3 if time is very short.
• Technical peers want method and caveats. Keep them in a backup slide and be ready to show it.
• Mixed audiences: main story for everyone, appendix for detail.

Ask in advance: how much time do I have, what do they already know, and what decision can they actually make?

Be honest about uncertainty

Storytelling can slide into overselling. Protect your credibility:

• State sample sizes and time periods.
• Give ranges, not false precision.
• Say what the data cannot tell you ("this shows association; the A/B test will show cause").
• Do not cherry-pick a date range that flatters the result.

Worked example: rehearsal checklist

Before presenting, run through:

1. Can someone who sees only the slide titles repeat the message?
2. Does every chart support the message on its slide?
3. Is there one clear ask?
4. Can you give the whole story in 60 seconds without slides?
5. Have you prepared answers for "how do you know?" and "what if you are wrong?"

Common mistakes

• Walking through the analysis in the order you did it ("first I cleaned the data...").
• Several messages competing on one slide.
• Default chart titles such as "Funnel by step".
• No recommendation, just "interesting findings".
• Hiding caveats until someone asks.

Quick recap

• Write the one-sentence big idea before building slides.
• Three slides: context and question, key evidence, recommendation and ask.
• Takeaway titles, one highlighted chart per slide, annotations, rounded numbers.
• Be clear about uncertainty; it builds trust.

Try it

The Do tab has you build and present a three-slide data story from an analysis you have already done.