The meeting's on the calendar: a quarterly update for a client, a walk-through for the bank, a pitch to a partner. The notes exist, spread across a notebook, two email threads and last month's figures. The slides don't.

Q3 revenue

Revenue

Repeat clients

Next steps

A topic, not a claim

Repeat clients paid for most of Q3

Chart: revenue by client, from your notes

A claim, with the evidence under it

Fig. 1One slide, titled two ways, with the prompt's own examples. Michael Alley's assertion-evidence approach puts the slide's main message in its headline, with the evidence under it. A sample slide.

AI deck tools will make slides from a topic alone. What comes back tends to look finished and say little, and any number on it may have come from nowhere.

So decide what each slide claims first, from your own notes, and let the design tool only lay it out.

01Done
Put the notes in one file and write the ask
Gather everything into one plain text file: the meeting notes, the figures from your accounting export, the email where the client said what they want. Copy numbers exactly as the source writes them, with the source beside each one.

Then write three lines at the top:
- who's in the room
- the one thing you want them to decide
- how many minutes you have
A deck with no ask ends on a thank-you slide and a silence.

Take out what the deck doesn't need before any of it goes into a chat window: payment details, staff pay, anything a client told you in confidence.
Checkpoint
One notes file with the audience, the ask and the minutes at the top.

Turn the notes into a slide outline

the step that pays off

Run the prompt below in Claude or ChatGPT. Each slide gets one claim as its title and the evidence under it.

Michael Alley at Penn State calls this the assertion-evidence approach: a sentence headline that states the slide's main message, supported by visual evidence. So the prompt asks for a chart, a table or a photo where your notes hold one, and short lines only where they don't.

[ASK: ...] does the most work. A model with a gap in the notes tends to fill it with a plausible figure, and a plausible number in front of a bank is worse than a blank. Answer each one in your notes file, then run the prompt again, so the notes stay the one source.

Read the slide titles alone, top to bottom. If they tell the story without the evidence, the outline's done.

Turn the notes into a slide outline

I have to present to {{AUDIENCE}}. The one thing I want them to decide
or do at the end: {{THE_ASK}}. I have {{MINUTES}} minutes.
Turn my notes below into a slide-by-slide outline. Rules:
- One claim per slide. The slide title is that claim, written as a full
  sentence of 15 words or fewer. "Q3 revenue" is a topic, not a claim.
  "Repeat clients paid for most of Q3" is a claim.
- Under each title, the evidence for that claim, taken only from my
  notes. Where the notes hold figures that show it, name the chart or
  table that would show them and list the exact figures it uses. Where
  a photo would show it, name the photo. Only where no visual fits, use
  two to four short lines.
- Every number, date, name, price and quote must come from the notes
  below. If it is not in the notes, you do not know it. Where a slide
  needs a fact the notes do not have, write [ASK: the question] in its
  place. Never estimate, round, or combine figures into a new number
  unless you show the sum.
- The last slide states the ask in one sentence, word for word as I
  gave it above.
- No more than one slide per minute. Fewer is fine.
- No adjectives about my business and no buzzwords. Plain words a
  busy reader gets in one pass.
Return plain text in this shape:
Slide 1: (the claim)
Evidence: (the chart, table or photo, with the figures it uses, or two
to four short lines)
After the last slide, add a section called "Numbers used". List every
number, date and price in the outline, one per line, with the slide it
is on and the exact line from my notes it came from.
Notes:
"""
{{YOUR_NOTES}}
"""

Checkpoint

An outline with no ASK notes left and a Numbers used list at the end.

03Done
Build and brand the deck in Gamma
Paste the outline into Gamma's agent. It builds the whole thing by default, research and images included.

Add "use this text as-is, add no images and no web research" to your prompt. Gamma's help centre says "use this text as-is" makes the agent build around your text instead of rewriting it. A rewrite is how a number drifts.
- Pick Express in the mode picker to skip the questions. Research only runs in Plan mode.
- Attach your own photos in the prompt bar before you generate.
- The older Paste mode, with a Don't add images option, is in the classic generator.
Brand it from a deck you already send: import a .pptx as a new theme. Gamma reads its colours, fonts and logo and shows you what it found to check. Then apply that theme to your gamma.

Export it as PowerPoint or PDF. Choose All cards, or only the current card may be exported. On Gamma's Free plan, PDF and PowerPoint exports carry a Made by Gamma badge. Gamma embeds the theme's fonts in the .pptx, but Google Slides ignores them, so open the file on the machine you'll present from.
Pro tip
If the words are right and the look is wrong, ask the agent for a restyle. Regenerating starts the content over.
Checkpoint
A branded deck, exported, with every slide title from the outline.

Or build the .pptx in Claude instead

Rather skip a design tool? Claude can write the PowerPoint file itself. Anthropic's help page lists .pptx among the files Claude creates.

The setting is Code execution and file creation. The file downloads from the chat or saves to Google Drive.

Fill in your brand colours and fonts and paste the outline into the prompt below. It asks for plain layouts, so the slides carry the outline's words and little else.

Open the file in PowerPoint before you trust it. Anthropic's own page says you may need to review and refine what Claude makes.

Build the .pptx from the outline (Claude)

Build a PowerPoint file (.pptx) from the outline below. Rules:
- One slide per "Slide" entry in the outline, in the same order.
- The slide title is the outline's claim, word for word.
- The slide body is the outline's evidence. Where it names a chart or
  table, build it from the figures listed in the outline and no others.
  Where it names a photo, leave a labelled placeholder. Where it gives
  lines, use them word for word. Do not add, remove, round or reword any
  number, date, name or price.
- If any [ASK: ...] note is still in the outline, put it on its slide in
  red so I cannot miss it.
- Brand colours: {{BRAND_COLOURS_AS_HEX}}. Headline font:
  {{HEADLINE_FONT}}. Body font: {{BODY_FONT}}.
- Leave the "Numbers used" section off the slides.
- Plain layouts. No stock photos, no icons, no clip art.
When the file is ready, list any slide where the text did not fit and
what you did about it.
Outline:
"""
{{YOUR_OUTLINE}}
"""

Checkpoint

A .pptx with one slide per outline entry and any ASK notes in red.

05Done
Trace every number back to the notes
Any step that lays out text can also change it: a shortened line, a rounded figure, a chart the outline never asked for. So check the deck you'll show, after the design pass. Any chart or figure Gamma drew counts as NOT IN NOTES until the check finds every value in your notes.

Export it as a PDF and attach it in Claude or ChatGPT with the prompt below. OpenAI's help page lists PDF among the files ChatGPT takes. Paste your notes file where the prompt asks for it.

Fix every CHANGED and NOT IN NOTES line in the deck. Run the check again until it ends on matches the notes.

That only means the deck agrees with your notes. The last pass is yours:
- hold each figure in the Numbers used list against the spreadsheet or email it came from
- read the deck once as the person you're presenting to
Check every number on the slides against the notes
Below are two things: the text of a presentation, and the notes it was
built from. Check the presentation against the notes. Do not rewrite or
improve anything. Only report.
1. List every number, percentage, date, price, name and quote on the
slides. For each one, give the slide number and one of:
- MATCH: it appears in the notes exactly.
- CHANGED: it appears in the notes in a different form. Show both.
- NOT IN NOTES: it does not appear in the notes at all.
2. List any claim on a slide that the notes do not support, with the
slide number.
3. List any [ASK: ...] note still left on a slide.
Treat every chart, table and figure on the slides as an item in 1, and
check each value it shows.
End with one line: "matches the notes" if every item in 1 is MATCH and
nothing is listed in 2 or 3. Otherwise "fix before sending".
Presentation (pasted slide text, or the attached PDF):
"""
{{DECK_TEXT}}
"""
Notes:
"""
{{YOUR_NOTES}}
"""
Checkpoint
A check that ends on matches the notes, and every figure held against its source by you.

The takeaway

A deck where every slide makes one claim, every number traces to a line in your notes, and the look matches the decks you already send. The outline and the check are the parts that protect you. The design tool is swappable.

The limit: this checks the deck against your notes, not your notes against the truth. If the spreadsheet you copied from is wrong, the deck is wrong with confidence. It also won't decide what to ask for. That last slide is yours to write.

Variations

The same client next quarter. Keep this quarter's outline. Next time, paste it above the new notes with "keep the same slide order and change only the claims the new figures change." The client reads the same structure and sees what moved.

A bank or lender meeting. Add two rules to the outline prompt: every figure names the period it covers, and every forecast is labelled as a forecast.

The team version. Same notes, a different ask: what each person needs to do and by when. Change the audience and the ask and run the outline again. The evidence lines change because the decision changed.

A one-pager instead of slides. Gamma makes documents as well as decks. Ask the agent for a one-page document from the same outline, for the reader who won't sit through slides, and run the number check on it too.

Don't start from a topic. Typing "Q3 update for our biggest client" into a generator skips the outline, and the outline is the part that keeps the numbers yours.