Key Takeaways — Chapter 30: Slide Design

The summary card. Use it to re-ground before the quiz, or to review weeks later.

The one idea

A slide is a visual aid, not a document you project. The audience can read OR listen, never both — text and speech fight for the same verbal channel — so a text-dense slide doesn't support your talk, it competes with it, and it wins (this is death by PowerPoint). The fix: let the slide carry the one thing words can't (a picture, a relationship, a number) and let your voice carry the argument. Once you cross this threshold, you stop writing slides and start designing them. (Chapter 18 walked you across this line for research talks; here it's general — every talk you'll ever give.)

🚪 Threshold concept: A slide is a visual aid for a talk you give with your voice; the audience reads OR listens, never both. Before, a slide felt like a page you project that should stand on its own. After, your spoken words carry the meaning and the slide shows the one thing words can't.

The assertion–evidence slide (the central technique, for any talk)

  • Title = a full-sentence assertion — the one claim you want remembered. "Slow onboarding drives 7× more churn" ✅, not "Findings" ❌.
  • Body = one visual (chart, photo, diagram, or a big number), labeled directly — no bullets, almost no body text.
  • The title is the slide's caption (Chapter 9): it states what the visual means, so a viewer who reads only the title still leaves with your point.
  • It beats the default topic-and-bullets slide on all three of that slide's failures: the title now makes a point, the visual doesn't compete with your voice, and the slide has exactly one job.

The concrete limits

  • One point per slide. If the title needs an "and," that's two slides. Slide count is free; audience attention is not. Ration points, not slides — and never cram into fewer, denser slides to "save time" (time is set by what you say).
  • ~6-word ceiling on a topic title — a diagnostic tripwire: a topic that overflows is a slide hiding more than one point, so split it, don't shrink the font. (Assertion titles are full sentences and may run a dozen words.)
  • The back-row test — read the title and labels from the back of the room (or a shrunk slide from six feet). Big type (titles ~28–40 pt, nothing important below ~24); when text won't fit, cut the text, never the font.
  • Contrast ≥ 4.5:1, checked with a tool (Chapter 10) — projectors wash out contrast that looked fine on your bright laptop. Never encode meaning by color alone — pair it with a label, shape, or position; run the grayscale glance.
  • Data-ink on the chart (Chapter 9) — rebuild every chart for projection: one comparison, direct labels, axis at zero, one accent color, no gridlines/3-D/legend/logo. Pasted exploratory charts fail on a projector.

Animation: clarify or cut

  • Use it when a build assembles a multi-part visual in sync with your narration — each piece appears as you say it, so attention follows your words.
  • Cut everything else: flying/spinning/bouncing bullets, fancy slide transitions. The eye chases motion, so gratuitous animation pulls attention off your point.
  • The test: does the motion carry meaning, or is it there to look interesting?

Templates and the 10/20/30 rule

  • Template, not theme: take the template's surface (font, color, spacing, layout) but override its content structure (kill the prefab agenda and bulleted layouts; use assertion–evidence). "Generic" comes from thoughtless filling, not from templates (Chapter 10).
  • 10/20/30 (Guy Kawasaki): ~10 slides, ≤20 minutes, ≥30 pt font. Take the numbers loosely (a visual-heavy talk may run more than 10 slides while making ~10 points); use the rule as a final audit against the universal disease — too much. Spirit: few points, tight time, big type.

The "it depends"

A slide you narrate must aid listening. But a reserved reference slide (held for Q&A) may be dense — it's an appendix. A pre-read deck meant to be read silently is a document — write it as one. A mandated format (some clinical/legal/safety) constrains you — comply, then make the cleanest slide it allows.

Themes this chapter surfaced: #5 structure-serves-the-reader (the slide's title leads, the visual proves) · #7 the-best-writing/design-is-invisible (the slide aids the speaker and gets out of the way) · #2 audience-is-everything (the live listener who can't rewind) · #6 every-element-earns-its-place (one point per slide; cut chartjunk, cut gratuitous animation).

Threshold concept: A slide is a visual aid for a talk, not a document you project; the audience reads OR listens, never both.

Feeds forward to: Ch 31 (delivery — the deck is half a presentation; the human half is next), Ch 32 (diagrams and the build, in depth), Ch 37 (executive presentations and the one-pager).

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